Yeah. The US is a huge area with a relatively low population density and abundant natural resources. It participated in both world wars, and was nearly the only country to not take any real damage from either of them.

There hasn't been a war on US soil since the US civil war. There has barely even been any damage to a US state. In WWII they bombed Pearl Harbor before Hawaii was a state, invaded the Aleutian Islands before Alaska was a state, and one floatplane launched from a sub tried to set fire to the forests around Oregon and failed.

The countries that had been superpowers in 1900 were recovering from mass casualties and massive damage after 2 world wars.

It's no surprise that in Europe one of the only countries not to participate in WWII was Switzerland, and they're also rich today.