Eli whitney invented the cotton gin, but he is also credited with changing american manufacturing by putting another idea into practice. what is it?

Before the civil war, the constitution protected slavery -true -false

Which source would best a historian understand the effect of the great chicago fire on families? a. a biography of a chicago family displaced by the fire b. a letter from a grandmother in new york to her family in chicago c. a newspaper editorial about families who were displaced d. an oral history dictated by an adolescent who fled the fire

Yugoslavia a: nato b: warsaw pact c: not a member of either alliance