Dialogue in "Little Green Men" seemed to suggest the Vulcans didn't have warp drive in 1947.
This has been covered recently in another thread. Enterprise made it clear that Vulcans were warp capable and had a fleet of ships engaged in active exploration of space in the 1950s.
This leaves us with two theories:
-The Vulcans accomplished a lot in 10 years.
-Quark was wrong.