A problem with river travel was

hope this helps :)

Explanation:

In 1787, Fitch built a 45-foot steamboat that he sailed down the Delaware River while members of the Constitutional Convention watched. ... Because they were so expensive, his steamboats were unsuccessful. The first successful steamboat was the Clermont, which was built by American inventor Robert Fulton in 1807.

answer; i believe the two groups were irish immigrants and chinese immigrants;

there has only been 12 presidents. the 12th president is/was moon jae-in