If you are talking about the company as a whole, parks and entertainment, I think the biggest peak was around 1960-1964.
Disneyland had been open for five years and it was just as Mary Poppins was on the horizon. After Mary Poppins, the company took a bit of a downturn, especially after Walt died, that they really didn’t start to come out of, in my opinion, until the Disney Renaissance which began with The Little Mermaid. WDW was a help in the 70’s, but I don’t feel they hit their stride until the mid 1980’s, after Epcot had been open a few years and the resort began to grow with more parks and resorts.