In early stage of Space Race, it was Soviet Union leads and give unexpected surprise to US. But why US can overtake? There are two major concentrations, that is concentration of capital and concentration of talented manpower.
Just after World War II, there is a global recovery. Other countries are in labour intensive development but US in capital intensive development. In Chicago, the State and Madison Streets Corner once known as the busiest intersection in the world (From Congress Library)
Later surpassed by Times Square of New York. That means the first and second financial centres of the world are in US. Nowadays there are two famous Labor Day, the May Day (May 1st) is commonly celebrated the communist countries like Russia and China, the Labor Day of US is on the first Monday of September. But actually, two labour days are all generated from Chicago. Why? Because Chicago is the home for skyscrapers, therefore it needs large amount of labour workers, and thus labour problem is more important that any other cities. Building skyscrapers also needs to be capital and labour intensive. Therefore, both labour and capital are concentrated in US. Now New York and Chicago are still the two most important financial centres of US. CME already purchased Nymex and the headquarter of CME is in Chicago. The most important future trading is still in Chicago. Practically, the faculty of Economics in Chicago University always ranks number 1 in the world.
The concentration of talented manpower is also decisive. The idea of atomic bomb at first was generated in Germany, but The Chicago University recruited a number of refugee scientists from Europe who worked on the production of the world’s first human-caused self-sustaining nuclear reaction.
Later contributed to the Manhattan Project. The two atomic bombs of US ended World War II. All other countries follow the Manhattan Project to develop nuclear power. Why US is US? In Finance they have Wall Street, in technology they have Silicon Valley, in Space Race they have Houston Space Center. They are irreplaceable after all because all talented people are concentrated hoping to have a better development.
Nowadays the US are always having complain that China uses the Thousand People Project to transfer their intellectual property. That is, they send students to US to study technology from undergrad to postgrad and doctorate degree, and when gained the confidence of US they are allowed to enter into core research lab and transfer the intellectual property back to China. So, they banned all Chinese students to learn technology in US now. In the tariff war, Donald Trump even said he would ban all Chinese students including those from non-technology sector like commerce or arts, but never carried out. Why? For nowadays, the Ivy League and other famous university, Chinese students occupy an important part of their income. And in Wall Street, Silicon Valley and Houston Space Center, a lot of the core members are 2nd or 3rd generation of immigrants, including ethnic Chinese who are quite loyal to US.
It is hard to filter out who is loyal to US among numerous foreign students and immigrants and hard to cut all immigrant because of transfer of intellectual property.
Ideally, the lock should be on property and not on immigrants or students.
To sum up, the success of US is on centration of talented people, no matter which country in the world, those talented people wish to go to US to have better development in their sector. The concentration of capital provides chances for them to absorb talented people and in turn absorb more capital to make a prosperity cycle. Therefore, US is a place where ugly ducklings can change to swan, mountain chicken can turn to phoenix. The concentration of money and talented people in turn bring about concentration of chances where everyone wants to meet with the promising chances.