What were some important technological advances in the United States?

there were two technological innovations that profoundly changed daily life in the 19th century: steam power and electricity. The railroad helped expand the U.S.. The telegraph, the telephone, and the typewriter brought people together that were far away.

because mexico wanted to choose a centralized location

(b) britain had a much larger navy than the u.s.

(d) the u.s. had a small army compared to britain.