Origins of the main political parties

Here are two very interesting Vox videos about the evolution of our major political parties. 

From white supremacy to Barack Obama: The history of the Democratic Party 

Here is a short description from the video's bio:

"The Democratic Party is the longest-existing political party in the US, and arguably the world. But in its over 180-year existence, it's completed a remarkable ideological and geographic transformation. Originally a staunch defender of Southern slavery, the party now wins the support of most nonwhite voters. Once an advocate of rural interests against coastal elites, the party now draws much of its strength from cities and coastal areas. This video tells the tale of the Democratic Party's origins, its various metamorphoses, and the sources of its strength — and weaknesses — today."

How the Republican Party went from Lincoln to Trump

Here is a short description from the video's bio:

"Today’s Republican Party opposes big government. It’s culturally conservative. Its demographic support is strongest among white voters, and it usually dominates elections in the South. And its 2016 presidential nominee has been heavily criticized for inciting racial tensions.

But things weren’t always this way. Over the past 160 or so years, the party has undergone a remarkable transformation from the party of Abraham Lincoln… to the party of Donald Trump. "