This Map Shows Just How Much Democrats And Republicans Have Changed Since The 1900s

Today, Democrats dominate densely-populated urban centers and the coastal regions of the United States, while Republicans cover America's vast interior. For most of us, that is the only political reality we have known. However, it is actually a development of the last century.

The map above, created by Arizona State University's Jonathan Davis, shows just how much the American political landscape has changed. The map shows the election results in the House of Representatives for every election since 1918.

Perhaps the most glaring change is that Democrats used to dominate the Southern states. That began to shift, however, with the Civil Rights Act of 1967. During the signing of the bill, President Lyndon B. Johnson famously told Bill Moyers, "I think we just delivered the South to the Republican party for a long time to come." While Johnson was right, interestingly, the change was gradual in the House of Representatives, where the Democrats' Southern stronghold was slowly eroded over the course of 30-40 years.

Here are a few of the other developments that you can see in the map:

1920s-1930s : The Great Depression and The New Deal

Republicans dominated the electoral landscape in the 1920s with the country electing three consecutive Republican presidents (Harding, Coolidge, Hoover). However, the aftermath of the Stock Market Crash of 1929 moved the country to the left in 1930 and, as the Depression wore on, the country turned more and more Democratic. The real change-over happened in the 1934 Midterm Elections, during Franklin Roosevelt's first term, when the American people voted heavily Democratic in a show of support for the New Deal.

1990s- The Republican Revolution

In the 1994 midterm election, the first of Bill Clinton's presidency, the Republicans made huge gains in the House and Senate, picking up 54 and 8 seats respectively. The event was termed the Republican Revolution or the Gingrich Revolution (because Newt Gingrich became Speaker of the House as a result of the election). The election put the Republicans in control of Congress for the next three elections.

Gerrymandering

Another interesting development on the map is the way gerrymandering - the practice of redrawing the boundaries of congressional districts to benefit one party or demographic over another - has completely changed the map of the U.S.. While the practice has been around since the inception of the country, it has been increasingly used in the last 50 years to draw ridiculously shaped, often non-contiguous districts that blatantly disadvantage a political party.

This is what the districts in the U.S. looked like in 1918:

This is what it looked like in 2012, when the country is carved up like a jigsaw puzzle:

Here's the full map animation: