Some are nicely summarized (factors leading up to the current Political/Military/Economic domination) in a two-part Stratfor article;
1) The Geopolitics of the United States, Part 1: The Inevitable Empire - https://worldview.stratfor.com/article/geopolitics-united-st...
2) The Geopolitics of the United States, Part 2: American Identity and the Threats of tomorrow. - https://worldview.stratfor.com/article/geopolitics-united-st...
The way i look at it is (in no particular order);
Luck - WW2 decimated almost all developed countries. The US "home" was untouched (no war on their soil) thus leaving them as the sole industrial/military powerhouse with resources intact. This is actually a huge factor and the current state follows directly from here. They also appropriated a lot of Scientists/Technologies from the losers which gave them the needed headstart in many tech areas.
People psyche - The country was founded by immigrants who basically had to do whatever to "survive". Since they had no history in the new land, they were not bogged down by crystallized cultural norms and beliefs. Thus the focus on "Capitalism"(euphemism for Greed and "do whatever it takes to win") and "Hustle" (not always driven by Ethics/Morals contrary to what their leaders may claim). This setup their current culture where their desire is to be THE global hegemon by any means necessary. If you think about it, this is a great motivator for just about anything.
Geography - Covered well in the above articles. This allowed them to develop independently of detrimental external influences.
Control of World Economy - By forcing everybody to use $ as the world's currency. The ramifications of this is all-encompassing.
Military/Education/Industrial Complex - This is a crucial nexus which is directly responsible for much of their dominance in the technology domain. The Military funds "Blue Sky" projects in close association with Academia and the Industry. Because of this close-knit setup, the path from Ideation to Realized Implementation is very fast and seamless. No other country does this as well. Because of the "Power Law", progress in Technology is accelerated leading to being the natural front-runner.
Finally, it should be clear that "Military Dominance" is used to enforce "Economic Dominance" and vice-versa.