How did race, specifically Blacks fighting in the Civil War, unsettle how Whites in the North and South envisioned the future of the United States

Which is the best example of a primary source ducument useful in the study of history ?

The idea of liberalism in eighteenth-century british politics: a. had mainly a civic and social quality. b. prompted two eighteenth-century leaders, joseph mccarthy and hugh mccarran, to demand independence for ireland. c. brought great wealth and power to its main voice, john locke. d. was compatible with inequalities in wealth and well-being. e. had the same meaning as liberalism in twenty-first-century american politics.

What kind of contact did christopher columbus and native americans initially have?