Who was the president when the last 2 states joined the union?
Dwight D. Eisenhower
(During the Civil War) Abraham Lincoln
In 1952 there were 48 states in the US. They are sometimes referred to now as the 'lower 48', if the matter at hand is relevant only to the contiguous states below Canada. Like Hawaii, Alaska does not border any of the other states. The last two states to join the union were Alaska and Hawaii, both of which joined in 1959.
Each of the states joined the union at a different time, and it would be a very long answer to list all fifty of them. The first three were Delaware, Pennsylvania and New Jersey, all admitted in 1787; the last two were Alaska and Hawaii, both admitted in 1959. I enclose a link to a timeline of when each state was admitted to the union.