Did the Democratic Party invent slavery ? Slavery began around 1619. There was no Democratic Party then . The Democratic Party began to become anti-racist in the administration of Franklin Roosevelt in the 1930’s , reversing its role as the Party of the Ku Klux Klan which it was during Jim Crow ; and steadily became more and more the Party of anti racism ; finally electing a Black President as an emblem of its anti-racist policies. The Republican Party began to reverse its status as the Party of Abraham Lincoln ( who ended slavery) beginning especially with Richard Nixon’s “Southern Strategy “, pandering to racism in the South and North. Republican racism became stronger with Ronald Reagan, and much stronger with Trump.