A
regulate interstate commerce
The main difference between being poor in America and Europe in the 19th century etc. was that America offered much more opportunities due to the fact that it was a nation that was being built up from the ground. This meant that poor people and people of low education could at least get various jobs in construction and related things whereas in Europe, the opportunities for such people were much smaller.
Antarctica Australia and south america<span />
Primary source. is the answer i think
