Short answers, pulled from the story.
The Compromise of 1877 marked the end of Reconstruction and the withdrawal of northern troops from the South. This political deal decided the contentious presidential election in favor of Rutherford B. Hayes over Samuel J. Tilden while southern White elites gained freedom to impose discriminatory practices without federal interference.
In 1896, the U.S. Supreme Court established the doctrine of separate but equal in the case of Plessy v. Ferguson. This ruling upheld state-mandated discrimination in public transportation under the guise of equality and provided the legal foundation for Jim Crow laws throughout the South.
According to the National Negro Business League, the number of Black-owned businesses doubled rapidly from 20,000 in 1900 to 40,000 in 1914. There were 450 undertakers in 1900, rising to 1,000 over this time period.
The National Association for the Advancement of Colored People formed in 1909 through the efforts of W.E.B. Du Bois and others including Mary White Ovington and Oswald Garrison Villard. Du Bois became editor of its magazine The Crisis.
A. Philip Randolph took leadership of the Brotherhood of Sleeping Car Porters at its founding in 1925. The union eventually won recognition from the Pullman Company in 1935 after a ten-year campaign.
The political campaign saved all the defendants from the death sentence and ultimately led to freedom for most of them. Their legal campaign produced two significant Supreme Court decisions: Powell v. Alabama and Norris v. Alabama which extended the rights of defendants facing state criminal proceedings.