Remember that the U.S. still manufactures a lot of things. It is one of the largest manufacturers in the world (only recently surpassed by China in terms of raw output by a small margin last I checked). What has declined are manufacturing jobs due to improvements in technology. Outsourcing is not the sole source of loss of manufacturing jobs.
Regarding the economy's history, I think it's important to remember that post-WWII, that was a very unique situation the U.S. found itself in historically that led to such booming economic growth:
1) All of the major U.S. competition economically bombed-out due to WWII
2) The U.S. itself had spent the war building up a large amount of additional manufacturing capability
3) Certain European countries after the war focused on socialism (such as the United Kingdom) which hamstrung their economies, thus providing less competition for the U.S.
4) The infrastructure projects of the New Deal which had established a foundation that allowed formerly rural areas to develop into booming, thriving economies
5) The development of the Interstate Highway System, which allowed the growth of towns and cities
6) The massive amount of research and development into science and technology that happened during WWII in order to develop things ranging from computer technology to radar, sonar, radio, etc...(i.e. electronics), the atomic bomb, huge improvements in aviation and the internal combustion engine, materials science, etc...this provided a base of knowledge for industry to build off of post war.
7) The Cold War defense budget, which led to further massive research and development in science and technology
8) The Space Program, which was probably the greatest investment of money into research and development of science and technology in human history. The modern world would not exist if not for the space program. Silicon Valley would not exist if not for the space program. iPods, iPads, cell phones, the computer you are typing on, the Internet, satellites and all the things that have come from them (geology research for finding more oil and energy sources, understanding of the weather, communications, etc...), improvements in medical technology like CT scanners and MRIs, modern automobiles with all their computer technology, etc...none of it would exist if not for the space program. The space program and the Cold War defense budget, and if you go back far enough, the WWII defense budget, provided the R&D technological foundation to allow the private sector to create whole new industries and products, which partially contributed to the booming economy of the 1980s and 1990s.
9) I don't know the exact size of the contribution in terms of GDP growth, but after WWII ended, the U.S. stole a huge amount of patents from German industry
So I mean while yes the economy of the 1950s and 1960s was in many ways great, it was due to a variety of factors that are not likely to be repeated again any time soon.
