The company Kroc worked for prior to founding McDonald's, Prince Castle, still exists, and supplies McDonald's with much of its equipment.
While most productions shoot a minimum of twelve hours per day, this movie frequently shot for between eight and ten hours. This was due to the fact that John Lee Hancock came very well prepared and didn't overshoot anything he liked from the first take. Adding to the fact that the whole film was shot in only twenty-two days, this makes for an incredibly rare shoot.
Ray Kroc's "discovery" of McDonald's was not his first attempt at franchising (taking over) a Southern California restaurant. According to the book "In N Out Burger" by Stacy Perman, Kroc approached Los Angeles' Apple Pan restaurant in 1949, and Carl Karcher of Carl's Jr., prior to convincing the McDonald brothers.
While there were some hard feelings between the McDonald brothers and Ray, it wasn't as bitter as portrayed. The brothers were very happy with the huge retirement nest egg they'd gotten from the buyout and from their legacy. Dick even ate the ceremonial 50 billionth hamburger in 1984.
Dick and Mac really were as close in real life as depicted in the film. Sadly Mac died 27 years before Dick.