The USA is one of the most prolific nations in the Olympics. What factors have led to this dominance?

Money. Sports is big money in the USA.

Populous and rich. See also: China

Money/resources.

Propaganda.

Since I was downvoted, i.e. we pumped a lot of money into our Olympics teams to win as many medals as possible as a sign of strength, to use as propaganda. As did the soviets.

College sports.

Glowy