i'd seen a p-51 plane, but i'd never really, truly, understood what it meant. >> matt quy: take your time. >> pelley: before donating the plane, known as a pt-13, the quys carried the last of the airmen back to the air. >> matt quy: and it was just great to sit back in the back seat and look at this real tuskegee airman in a real tuskegee airplane. just magical. >> leo gray: the greatest thrill in my life was sitting in the seat where you are and watching the ground drop out from underneath me. the pt-13 was the baby that we used to learn how to fly. >> pelley: the smithsonian collected the thoughts of lieutenant colonel leo gray in 2010. >> gray: they said we couldn't fly. but we had the best record of any fighter group in the 15th air force, and probably in the air force itself. we stayed with our bombers, we brought them home as best we could. and we proved that we could fly. >> pelley: time is the enemy of history, so smithsonian conservationists have been working for years restoring america's heritage from textiles to trains. this 1920 railcar had two sections-- "white" and "colo