During the american civil war, the 54th massachusetts regiment is most noteworthy for

During the American Civil War, the 54th Massachusetts regiment is most noteworthy for being entirely formed by African-American soldiers.

Explanation:

The 54th Massachusetts Infantry Regiment was the first regular military unit in US history that consisted entirely of African Americans, with the exception of officers. It was created in 1863 in order to strengthen the Army of the Union that was at war with the Confederacy, during the Civil War.

i think it should be slowed colonial western march

the answer to your question is a. the salt plains

in 1811, he led an expedition, known as the george c. sibley expedition, to improve relations with the pawnee and kansa tribes, and also to locate the rumored jefferson's salt mountain