Which country did the united states purchase florida from in 1819?
a. great britain
b. mexico
c. spain
d. russia

the us constitution is a living document, meaning that it can be changed over time as the country changes.

during the 20th century, the role of the vice president has evolved into more of an executive branch position. now, the vice president is usually seen as an integral part of a president's administration and presides over the senate only on ceremonial occasions or when a tie-breaking vote may be needed.