Did progressives help minorities

No. They never have. From the Missouri Compromise, the Kansas-Nebraska Act, the Civil War, The KKK during reconstruction, Jim Crow Laws after reconstruction, and opposing Kennedy & Johnson when they proposed Civil Rights legislation, the home of the so-called progressives - the Democrat Party - has been on the wrong side of the issue. Either by expanding slavery in the US, fighting a war against abolishing slavery, or keeping minorities from being able to vote, use the same businesses and mass transportation as the majority, etc.

That is probably why Dr. Martin Luther King Jr. was a Republican.