The Founder is about the early years of McDonald’s and how Ray Kroc (played by Michael Keaton) came to gain control of the company. The official McDonald’s corporate history glosses over the events of the film in a few sentences:
In 1954, he visited a restaurant in San Bernardino, California that had purchased several Multi-mixers. There he found a small but successful restaurant run by brothers Dick and Mac McDonald, and was stunned by the effectiveness of their operation. They produced a limited menu, concentrating on just a few items-burgers, fries and beverages-which allowed them to focus on quality and quick service.
Kroc pitched his vision of creating McDonald’s restaurants all over the U.S. to the brothers. In 1955, he founded McDonald’s System, Inc., a predecessor of the McDonald’s Corporation, and six years later bought the exclusive rights to the McDonald’s name. By 1958, McDonald’s had sold its 100 millionth hamburger.
Kroc’s Wikipedia entry provides more flavor:
The agreement was a handshake with split agreement between the parties because Kroc insisted that he could not show the royalty to the investors he had lined up to capitalize his purchase. At the closing table, Kroc became annoyed that the brothers would not transfer to him the real estate and rights to the original unit. The brothers had told Kroc that they were giving the operation, property and all, to the founding employees. Kroc closed the transaction, then refused to acknowledge the royalty portion of the agreement because it wasn’t in writing. The McDonald brothers consistently told Kroc that he could make changes to things like the original blueprint (building codes were different in Illinois than in California), but despite Ray’s pleas, the brothers never sent any formal letters which legally allowed the changes in the chain. Kroc also opened a new McDonald’s restaurant near the McDonald’s (now renamed “The Big M” as they had neglected to retain rights to the name) to force it out of business.
See also some early McDonald’s menus.