History of the United States

Not always. Some men are more intelligent than some women, but at the same time some women are more intelligent than some men.

He was riding in a "whites-only" train car. Front of the marker placed Feb. 12, 2009, commemorating the planned arrest of Homer Plessy June 17, 1892, for violating the Louisiana 1890 Separate Car Act. He was sitting in the whites' coach when he was asked to move and refused, which led to his arrest.

I think you mean "Was Why?"

Meatpacking

If you had a black ancestors, you were considered black, regardless of your actual color.

Ida B. Wells

The author was pointing out how the sellers of the beef were uncaring.

Northern cities were segregated by customs, not by laws.

dominated industries so much that other companies could not compete

The issue that wouldn't concern most progressives would be racial segregation in the South.

President Theodore Roosevelt was against the misuse of power by the big corporations doing business as a trust or monopoly.

african americans

Gave women the right to vote.

All of the above