Oklahoma City
By the time Oklahoma was admitted to the Union in 1907, Oklahoma City had surpassed Guthrie, the territorial capital, as the population center and commercial hub of the new state. Soon after, the capital was moved from Guthrie to Oklahoma City. Oklahoma City was a major stop on Route 66 during the early part of the 20th century; it was prominently mentioned in Bobby Troup's 1946 jazz classic, "(Get Your Kicks on) Route 66", later made famous by artist Nat King Cole.

Q: What year was Oklahoma city entered into the Union?
1907