What are good secondary sources for the March 7 1965 "Bloody Sunday" event?

Alabama . gov has some great sources one titled Civil Rights Movement Unit:

Marching for Justice - Selma to Montgomery, is highly recommended

and there is a great  video by Visionary Project titled Amelia Boynton Robinson: Marching in Selma

Explanation:

while it was true that the cotton gin reduced the labor of removing seeds, it did not reduce the need for slaves to grow and pick the cotton.

explanation:

before eli whitney's invention of the cotton gin, picking and cleaning cotton was a slow, labor-intensive job. workers, usually slaves, had to pick the seeds from the cotton fibers by hand. this invention made it possible to grow large amounts of cotton on big farms and make money.

hitlers fav so e: jews