James Monroe is defiantly an overlooked President. Sadly for the last Founding Father to become President he was often forgotten.
Monroe started his Presidency during the height of the Era of Good Feelings. Which was when the Federalist party shrinked and collapsed, leaving Democrat-Republicans with no real political opponents. Monroe had no problem crossing party lines, and working with the now very small minority party.
The Panic of 1819 happened just a year into his presidency. The first real finical crisis of the newly formed and stable government of the United States. Despite being a panic, it was only a taste of what was to come later in American history.
Also in his presidency was the Missouri compromise. Which banned slavery in the new territories except the proposed state of Missouri. Even though they couldn't get the full new state ban, at least they kept some of the new land as a free state.
The Seminole Wars was also a big part of his presidency. After many conflicts down in Florida, the United States simply paid most of the Seminole Native Americans to move westward.
Spain was also an issue of concern over the wars. Andrew Jackson pissed them off by invading part of the land on the President's authority, though Monroe denied this later. Through help by John Quincy Adams, America bought Florida from Spain for about $5 million and dismissing any claims to Texas.
Monroe's biggest contribution was that of the Monroe Doctrine which was ironically wrote by John Quincy Adams. It basically praised all the Spanish colonies in Latin America for revolting. It also stated that the United States should stay neutral to all European-linked wars, and that Europe needs to know what boundaries are.
I can't really say too many negative things about Monroe. However for a two-term presidency he didn't do too much historically besides ceding Florida, and his Doctrine.