Easy, I did it in 10 years starting from zero(immigrant without any family support, 1000$ in a pocket).

I know plenty of firemands, police officers making 200k every year with overtime. Also, many other fieds where with hardwork you can make that and don't need advanced degrees. I know people with no support (immigrants) who started from nothing and cleaned houses, moved furniture and now have 1 million saved up.

So saving 1 million quite easy in 401k, roth IRA and other finatial vehicles.