Our chief sources for A Visual History of the Supreme Court of the United States are listed below:

Epstein, Lee, Thomas G. Walker, Nancy Staudt, Scott Hendrickson, and Jason Roberts. (2010). “The U.S. Supreme Court Justices Database.” Chicago, IL: Northwestern University School of Law, January 26.
http://epstein.law.northwestern.edu/research/justicesdata.html.

Andrew D. Martin and Kevin M. Quinn. 2002. “Dynamic Ideal Point Estimation via Markov Chain Monte Carlo for the U.S. Supreme Court, 1953-1999.” Political Analysis. 10:134-153. http://mqscores.wustl.edu/measures.php.

The Oyez Project. http://www.oyez.org/.

U.S. Department of Justice. “Solicitors General of the United States.”
http://www.justice.gov/osg/aboutosg/sglist.html.

Hogue, Henry B. CRS Report for Congress, “Supreme Court Nominations Not Confirmed, 1789-2004,” 21 March 2005.
http://fpc.state.gov/documents/organization/50146.pdf [PDF].

The information we used regarding the presidents (dates of terms, etc.) are widely available. We used workers in Amazon’s Mechanical Turk service to fact-check our names and dates. We initially approached Mechanical Turk as an experiment in outsourcing fact-checking; the work we received from its workers ran the gamut from useful to wacky. The useful work, though, proved the experiment to be worth it — we received thoughtful comments on everything from design and layout to the presentation of the data itself.

Wikipedia. http://en.wikipedia.org/. A note on Wikipedia: We find Wikipedia to be a highly useful source for finding information quickly. However, since it is an open platform (http://en.wikipedia.org/wiki/Citing_Wikipedia), we made sure to corroborate any first findings on Wikipedia with other sources.

Erin Miller of SCOTUSblog interviewed Nathaniel before the holidays, and she posted an edited version of the interview on the SCOTUSblog website. In case you missed it, the interview is reprinted below. Leave your comments!

“A Visual History of the Supreme Court of the United States”: A new artistic project about the Court

Posted by Erin Miller | Friday, December 18th, 2009 4:49 pm

If you (like us) keep going back to the Wikipedia list of Supreme Court justices since 1789, you might try a more aesthetic way to get your information: the new Timeplots poster, A Visual History of the Supreme Court of the United States. The “niche info art” poster, which went on the market last week, displays in granular detail the entire history of the Court’s justices, cases, and context. You can see a zoomable image of the poster (and purchase it) at the Timeplots website here.

The poster plots the timeline of the Court’s justices on one axis against a measure of their relative appointment by Republican or Democratic presidents on the other. But into that basic structure it sneaks a wealth of other information about the Court’s important decisions, events, and personnel.

The Supreme Court poster is just the first of many planned “Timeplots” of institutions by the start-up Timeplots, Inc. I interviewed the company’s founder, Nathaniel Pearlman, about his project earlier this week. The content of this post largely comes from him.

The original vision:

It all started with a class Pearlman took at Yale a couple of decades ago on visualizing information and a job in election data services that he had in the early 90s with a company that produced election maps, but Pearlman only had a chance to begin work on his ideas this year. (Timeplots runs out of the corner of the political technology company he founded in 1997, NGP Software, Inc.) Pearlman, who at one time was a doctoral candidate at MIT studying American politics, has long been interested in the Supreme Court, an institution that he describes as “central to the Republic.”

The poster’s intent is to capture the “entire sweep” of the Court’s history, both the minute details (what was the confirmation vote of Justice John Clarke?) and the big picture (which ten justices were most notable?). The way he describes it, “you can either zoom into the history in detail or walk back from it and see it all.” A secondary aim is to honor the individuals involved in the Court over time.

Research behind the poster:

The “Visual History” was in the works for many months. Most of that time was dedicated to planning the visualization and generating it — but a good deal was spent researching the impressive array of facts.

The poster includes timelines of justice appointments, chief justices, Solicitors General, the presidents and parties who nominated each justice (including a visualization of the relative influence of each president on the Court), the ideological slant of the Court (reflected in an a separate graph of the most liberal and most conservative justices each Term); momentous events (like the ending of the justices’ duty to “ride circuit” in 1891); constitutional amendments; as well as lists of landmark cases, the justices and their basic biographical facts, notable justices, notable unconfirmed nominees, and longest-serving justices. The data about ideological scores for decisions comes from political science and law professor Andrew Martin, whom the blog recently interviewed about the Supreme Court Database he coordinates.

Judgment calls:

Much of the factual information on the plot is publicly available. But Timeplots included some features on the poster that require judgment, like a list of the ten most “notable” justices and the selection of fifty-plus “landmark” cases. Pearlman consulted with constitutional scholars and lawyers on these lists, but welcomes more feedback; he will consider changing them with future updates of the poster.

Another set of decisions for the poster-makers was which momentous events to include on the graphic. For example, the timeline notes the appointment of the first Jewish justice and the only resignation by a justice.

The parties of the presidents who appointed the justices and the partisan make-up of the Court are centrally displayed on the timeplot (as the y-axis, in fact). But Pearlman isn’t necessarily suggesting by that choice that politics sway the Court’s decisions. Rather, he says the poster’s objective depiction of the facts lets observers come to their own conclusions about the nexus between the Court and the president. In fact, he notes (even on the poster) that the Timeplot data demonstrates that the link between the ideological slant of decisions and the party whose presidents appointed a majority of the justices is weak over time.

Future plots:

The next two planned posters, Pearlman says, are on the Presidency and Congress. Pearlman says he has a list of at least fifty more subjects that he would like to tackle if things go well, but for now they remain under wraps.

What would a “visual history” of SCOTUSblog look like?

When I asked him this question, Pearlman showed his mastery of the art of visualizing information by rattling off rapid-fire a list of details he would need about the blog: the number of visitors, when our contributors started working and their tenure, the subjects we have covered during the last five years, and even the frequency of the words that we use.

Just for fun – intrigued by Pearlman’s words – I generated a word cloud of SCOTUSblog on the web application Wordle.

More information about “A Visual History” is available on the company’s blog, here. Pearlman can be reached at ngp@timeplots.com.

While compiling the data that went into our Supreme Court Timeplot, a few justices stood out from the crowd. The name “Lucius Quintus Cincinnatus Lamar II,” the 50^th justice of the Supreme Court, sparked my curiosity—so I looked into it.

L.Q.C. Lamar was named after his father, who was named after the ancient Roman consul and dictator Lucius Quinctius Cincinnatus. Interestingly, LQC II’s father’s brother was the second president of the Republic of Texas; named Mirabeau Buonaparte Lamar, they were apparently both named after historical heroes of their eccentric uncle.

L.Q.C. Lamar had quite the career before he was nominated to the U.S. Supreme Court by President Grover Cleveland in 1888.

Lamar was elected to numerous political offices, serving in the Mississippi and Georgia state houses and the U.S. House in 1856 (from which he resigned following the founding of the confederacy). He was the drafter of the Mississippi Ordinance of Secession, and was Confederate Foreign Minister to Russia. After the Civil War, Lamar directed the University of Mississippi School of Law, where he introduced the “case method” of law school study. Lamar returned to U.S. House from 1873-77, served in the U.S. Senate from 1877-1885, and as Secretary of the Interior from 1885-88.

L.Q.C. Lamar was profiled in John F. Kennedy’s Pulitzer Prize-winning Profiles in Courage. He was noted for the courage of his eulogy of Northerner Charles Sumner, the vocal abolitionist senator from Massachusetts. Sumner had been vilified in the South during the Civil War. When L.Q.C. delivered Sumner’s eulogy, his words and his passion apparently caused congressmen on both sides of the aisle to weep openly. Press reports across the nation were effusive in their praise.

Here is the closing portion of his speech:

Bound to each other by a common constitution, destined to live together under a common government, forming unitedly but a single member of the great family of nations, shall we not now at last endeavor to grow toward each other once more in heart, as we are already indissolubly linked to each other in fortunes?

Shall we not, over the honored remains of this great champion of human liberty, this feeling sympathizer with human sorrow, this earnest pleader for the exercise of human tenderness and charity, lay aside the concealments which serve only to perpetuate misunderstandings and distrust, and frankly confess that on both sides we most earnestly desire to be one ; one not merely in community of language and literature and traditions and country; but more, and better than all that, one also in feeling and in heart? . . .

I know well the sentiments of these, my Southern brothers, whose hearts are so infolded that the feeling of each is the feeling of all; and I see on both sides only the seeming of a constraint, which each apparently hesitates to dismiss. The South prostrate, exhausted, drained of her lifeblood, as well as of her material resources, yet still honorable and true accepts the bitter award of the bloody arbitrament without reservation, resolutely determined to abide the result with chivalrous fidelity; yet, as if struck dumb by the magnitude of her reverses, she suffers on in silence.

The North, exultant in her triumph, and elated by success, still cherishes, as we are assured, a heart full of magnanimous emotions toward her disarmed and discomfited antagonist; and yet, as if mastered by some mysterious spell, silencing her better impulses, her words and acts are the words and acts of suspicion and distrust.

Would that the spirit of the illustrious dead whom we lament today could speak from the grave to both parties to this deplorable discord in tones which should reach each and every heart throughout this broad territory: “My countrymen! Know one another, and you will love one another.”

Our Timeplot of the history of the Supreme Court features 53 landmark cases from the beginning of the Court to present day. For each case, we indicate how each of the justices on the Court at the time voted. As one of our reviewers noted, choosing that list of cases is a fairly subjective process, but makes for a pretty good parlor game.

So how did we decide which cases to include? We consulted a variety of lists of landmark cases published by various academic and historical institutions, and we consulted with a number of serious students of the Court—people like lawyers, professors of law, and political scientists specializing in American history.

Some more prominent cases, like Marbury v. Madison, Dred Scott, or Roe v. Wade, would likely make anyone’s list of the top fifty or so. Others are more debatable. How would you have revised the list? Leave us your comments.

As we were creating our Timeplot of the history of the Supreme Court, we wanted to clearly display the influence of each U.S. president on the Court in an objective, non-partisan manner. To do this, we chose to measure influence by comparing the number of each president’s “justice days”—in other words, measuring how many days an appointed justice served (or in the case of recently-appointed justices, are predicted to serve) on the Court.

We created semicircle “bubbles” aligned to each president’s spot on the timeline and sized to each president’s total number of “justice days.”

Each half circle is colored by the president’s political party, so that it’s apparent at a quick glance that a few presidents have had an outsized ideological influence, at least by our objective measure. George Washington, Andrew Jackson, Abraham Lincoln, Franklin Roosevelt, Dwight Eisenhower, and Ronald Reagan have clearly outsized semicircles, indicating a high amount of influence on the Supreme Court of their day.

Of course, establishing a clear correlation between simply appointing justices and significantly affecting the Court’s ideology is tricky business—as Eisenhower’s appointments of the liberal Justices Warren and Brennan demonstrate, after being appointed to a lifetime term, a justice will not necessarily reflect the political preferences of the appointing president.

The Supreme Court Timeplot incorporates a small feature that might be easily lost amongst the large amount of data in the chart: Next to their names on the lists on either side of the Timeplot, we have starred (*) the ten justices who we consider “most notable.”

This is quite a subjective consideration, so I thought I might say a few words on how we came to develop our list.

We consulted multiple academic sources which rate or rank the justices (there have been quite a number of surveys of scholars and practitioners).

Then we proposed our own list of ten, and sent it to our reviewers—they suggested one change, which we incorporated.

The top ten in the current version of the Timeplot are Marshall, Story, the first Harlan, Holmes, Hughes, Brandeis, Black, Frankfurter, Warren, Brennan. Would you revise that list? Why? Leave us your comments.

The Supreme Court chart visualizes the timelines of justices on the Court as a river, flowing up when there are more appointees by Republican presidents and flowing down with more Democratic appointees. (We take significant liberties with justices before the establishment of those two parties, aligning Democratic-Republicans with Democrats and aligning Whigs and Federalists with Republicans.)

We know that many current observers view the progression of the Court through a partisan lens, assuming that Republicans aim to make a more conservative Court while Democrats seek to appoint more liberal members.

Ideology has always played a role in appointments, but our research proved that history is messy. We did not have an external measure of Court ideology that ran the whole period, but we did include as an inset a measure from 1939 to present day.

It is certainly interesting to note that the Court has at times had nine Democratic appointees or nine Republican appointees, but that the most liberal and most conservative landmark decisions do not necessarily correspond with those periods. We think the demonstrated variation over time in partisanship on the Supreme Court is a compelling component of our Timeplot. What do you think? How would you revise this for future versions of this Timeplot? Leave your comments.