Which folk singer led "We Shall Overcome" at the 1963 March on Washington, and later had a chart hit with her version of it?

After several years living in Vermont, which writer returned to Russia amid fanfare in 1994? After which poet died in 1886 did her sister Lavinia find hundreds of her poems in little handsewn booklets? After she died in 2003, McDonald's heiress Joan Kroc left about $1.5 billion to which charity? After she jumped into a demonic portal in 2001, whose TV gravestone read "She saved the world. A lot."? After her birth in March 1990, Buckingham Palace set up a phone line to tell callers how to pronounce which princess's… After signing the Mayflower Compact in 1620, John Carver became the first governor of which colony? In 1932 Sir James Chadwick discovered which particle, later used to split atoms in nuclear fission? After Smokey Robinson left which group, it had a No. 1 hit with "Love Machine (Part 1)", released in 1975?