Why is starting a business and being your own boss so much a part of the American dream?

Because you are lead to believe that you will no longer be a slave to a half brain nitwit ,and you will be the one calling the shots making the deals, and so on.
Sadly you become more of a slave than you ever were working for ole half brain.

@lynnk I don’t know that it is at all.

It’s about independence. Self determination. Personal sovereignty. These things run deep in our history, our political philosophy and in our culture.

It’s capitalism.

Autonomy. Being master of your own destiny. Having the freedom to determine what direction you take your business and career. Flexibility I terms of work hours. The ability to drive your own income.

It’s certainly not an easy option and as @SQUEEKY2 suggested, you are unlikely to work less hours. However, if you have employees you trust, you aren’t necessarily tied to a 9–5 existence.

I know my husband would not be happy working for someone else. He loves having the freedom to be innovative and creative and he’s making the decisions. Often after talking to his staff, but the buck stops with him.

Capitalism, self determination, autonomy, and the opportunity to climb the social ladder.

I’m not so sure owning your own business is the American dream. I think being free, having opportunities, being judged on your merit and not on your family name, I think the American Dream is just about being successful and safe.

My husband had always felt what he accomplished in America he probably never could have in his country, and he was working for corporations at the time. He had a corporate job, made good money, lived in a nice house, had an expensive hobby. I think that was just as much the American Dream as owning a business.

A lot of immigrants own businesses, because they can’t easily get jobs.

I’m not sure Americans necessarily want their own business any more than anyone else, we just have more opportunity for it than most.
Then too, lots of people in other countries have their own businesses, but not always with property attached. Lots of places have open air markets where wares of all sorts can be found.

I should add, I’m not an American and I agree with @Patty_Melt. This desire to own your own business is not a uniquely American trait. I don’t think it’s even a Western trait.