Which of the following objectives proved to be the hardest and took the longest to accomplish?

I believe it is the taking of Richmond that took the longest and was the hardest.

Explanation: Many soldiers on both sides lost their lives over four years of campaigning.

the government paid religious orders to provide basic education to native american children on reservations. in the late 19th and early 20th centuries, the bureau of indian affairs (bia) founded additional boarding schools based on the assimilation model of the off-reservation carlisle indian industrial school.