P Please introduce me to a reliable Source. Subject: the the main factor of Cont Countries lack of progress

in 1862, president lincoln's emancipation proclamation opened the door for african americans to enlist in the union army. although many had wanted to join the war effort earlier, they were prohibited from enlisting by a federal law dating back to 1792.

explanation:

the main objectives of the progressive movement were eliminating problems caused by industrialization, urbanization, immigration, and political corruption.

i am not 100   percent sure but i do know that hitler was burned to death with gas so that makes me think it is d. because they were under his control if they fail or not do as told they will be killed but i could be wrong hope this