The United States claimed the border lay at the

The United States laid claim to the territory from the Perdido River to the Mississippi River, which the Americans believed had been a part of the old province of Louisiana when the French had agreed to cede it to Spain in 1762.

Explanation:

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:

most people now work in jobs where they do one  kind  of work; they are carpenters, bankers, cooks, mechanics, and so forth. likewise, most  businesses produce  only certainkinds  of  goods  or  services, such as cars, tacos, or gardening  services. this feature of  production  is known as specialization.