We live in what is endlessly described as an era of unprecedented partisanship, with Americans polarized into red and blue camps and no convergence in sight. But much of the nation’s history was characterized by intense political rivalry, especially the late nineteenth century.

In 1876 the United States celebrated its centennial in the midst of a terrible depression sparked by the Panic of 1873. In some cities unemployment reached 25 percent, casting a significant pall over the celebration mounted in Philadelphia that spring. The mood worsened after the November presidential elections, which left Democrat Samuel Tilden in an electoral tie with Republican Rutherford Hayes. The atmosphere was chaotic, with accusations of voter suppression, rigged ballots, questionable returns, and eleventh-hour statehood for Colorado, which threw three crucial electoral votes to Hayes. The election was ultimately decided by a committee, which gave Republicans ongoing control of the White House.

This “Great Compromise” came during one of the most partisan periods in American history, and much of the staunch party loyalties had been forged in the recent Civil War. White Southerners were committed in their resistance to the Republicans for years after Appomattox, and by 1876 had coalesced into a bloc of unquestioned support for the Democratic Party that would last well into the twentieth century. In response, Republicans repeatedly “waved the bloody shirt” to remind Americans that it was they—the party of Lincoln—that had preserved the Union through the late war.

The riveting and decidedly partisan centennial election also coincided with the emergence of politics as a field of academic study. At its outset, “political science” focused on the evolution of American democracy and party behavior. This heightened interest in the nation’s political history prompted a slew of charts, maps, and graphs designed to make sense of the past “century of progress.” Among the most fascinating of these was Walter Houghton’s huge, elaborate chart of U.S. political history. A Midwestern educator, Houghton touted this as a “compass” to guide Americans through their complex political past.

At first glance the chart is disorienting, but it has its own internal logic. The top half is a straightforward timeline of elected leaders, important events, and landmark legislation rendered in ridiculously small type. It’s in the lower half where Houghton tried to find patterns in that chronology. He assigned a line to every party in electoral history, then measured the popular support for the party with comparatively thicker or thinner lines. The party occupying the White House is always placed on top.