In his book "The Art of the Deal," Trump describes his early days following his father around on the job.
"Almost from the time I could walk, I'd been going to construction sites with my father. Robert and I would tag along and spend our time hunting for empty soda bottles, which we'd take to the store for deposit money," he wrote in his book.
As a teen, he says he started going with his father to meet with contractors and collect rent "by being very tough and very relentless."
After graduating from the Wharton School at the University of Pennsylvania, he joined his family's real estate company full-time.