Monroe was the fourth president to come from the Old Dominion state and the third in a row after Jefferson and Madison.
The country up until this time was very much regionally defined, politicians were expected to be loyal to their fellow Virginians and Monroe was no exception. As most Americans, Monroe idealized Washington who by his time had become an almost mythical figure, his mentor was Jefferson whom he studied law under and Madison was at different times was a friend and a rival.
He came to power in the midst of the War of 1812 after serving as Secretary of State in the Madison administration. Up until this point, the Secretary of State was normal successor to the current President. Jefferson, Madison and Monroe had all served in the post.
Monroe appointed John Quincy Adams of Massachusetts, signaling a major change in the regional factionalism that had defined politics up until that point.
It should be noted that John Quincy Adams actually did become President after Monroe, continuing the normal path to succession. Much is written about the era of good feelings (reduction in Partisan politics) occurring around the time of Monroe's Presidency, but I believe not enough credit is given to him personally for helping to usher in this era through his cabinet appointment of a northeasterner.