Besides land, what did the united states gain from expansion?

The United States gained resources and gold which they reaped from the land. Also, California was controlled by Mexico for many years until the Mexican-American war, when America won the land. This vital victory gave them hoards of gold, oil, and coal, all useful and valuable materials

in february 1787, congress decided that a convention should be convened to revise the articles of confederation, the nation’s first constitution. in may, 55 delegates came to philadelphia, and the constitutional convention began. debates erupted over representation in congress, over slavery, and over the new executive branch. the debates continued through four hot and muggy months. but eventually the delegates reached compromises, and on september 17, they produced the u.s. constitution, replacing the articles with the governing document that has functioned effectively for more than 200 years.

by improved communication.