Actually the Saturn rockets that went to the moon were built at the Michoud plant in New Orelans, Louisiana.  Which also built the large Fuel cell and actual engines for the Space Shuttle (but not the O rings LOL).  I don't know if it still has tours, but it did prior to Hurricane Katrina.  We also hauled off tons of material from the Germans at the end of World War II and were willing to hire anybody who had worked on rockets on the simple theory that if they were working for us, they weren't working for the Soviets.  So if there was a rocket scientist in Yugoslavia he probably found easy immigration and money in the US.

We hauled every V-2 rocket we could lay hands on out of Europe, by marking them scrap metal and shipping them out through Italy.  It should be noted that Germany's rocket program was based on the work of American Robert Goddard according to Werner Von Braun.

Amongst Jets we retrieved the same air frame technology as the Soviets from the ME-262, but had the better engine that Rolls Royce had improved upon in her Gloster Metor, which was an improvement on our first Jet.

Technology is like two men racing up a ladder, if your competitor gets a rung you must too or lose the race.  This was graphically illustrated by Germany not being able to build a decent Strategic bomber, not copying a British or American design and losing the war by having her cities destroyed and Industry crushed.  You can't make mistakes like that and survive as a world power.