Of course it's possible to get rich in this country. I have two close relatives that are good examples. One served a prison sentence for a stupid act as a very young adult. When he got out, it was hard to get employment other than the construction business. After a few years, he had saved up a few thousand dollars and started his own construction company. Was it easy? No, but he's a very ethical, hard-working person in an industry full of shady characters and word got around. He's now a multi-millionaire with several million dollar-plus homes and his client list is full of names you'd know. Another relative took his inheritance from his grandfather (about $3000) and got some IT certifications. He worked his way up quickly at a fairly large company until he was making 6 figures. He saw a need and quit his job to start an IT staffing company. It was rough for a few years but he got over the hump, built the company up, sold it, and started another company with a different IT focus. That company sold for $30M a few years later, before he was 40.
Hell, for that matter my neighbor is a success story. She was a teacher all her life but lived as frugally as possible. She paid cash for her first and only house, and has been an avid investor all her life. She does a TON of research into every company she invests into, and it has paid off. She's been retired for as long as I've known her (20+ years), and has several million dollars to her name now. I'm sure she never made more than $50K in her life.