Easter Sunday and Pentecost because they are both Sundays and then Christmas Day.
But afaik, most Americans have to work on Sundays, anyway.
Not true.
Maybe it's just a cliché, but from what I heard the U.S. labor market policy isn't supposed to be very employee-friendly.
Employers are exactly as "friendly" as they have to be. If you do a thing better than most people that do that thing, your employer will treat you well. If you suck at your job, your employer will treat you like sh**t before firing you.
Most places are closed on the weekend. If you work in the service industry or a job that ya know, actually does an important thing (like doctor, firefighter, keeping the country safe) then you could potentially work at any day or time. I'm sure you have important jobs in Germany too even if you don't let people buy things on the weekend.
anyway, Christmas is the only religious holiday in the US and it shouldn't be a holiday in my opinion since we're NOT a Christian nation. That's only for those conservative European and S.American countries, not good, liberal places like the US.