Successive land sales allowed the Newhall family to maintain their lifestyle, but William (who was known by his middle name Mayo), a graduate of Yale University, understood that they needed a better way to generate income.

The land around their headquarters, the former Rancho San Francisco, was cleared for citrus trees and lima beans were planted in the Sacramento Valley.

He turned the operation over to his son-in-law, Atholl McBean, a San Francisco businessman who had held onto his entire savings during the Wall Street crash.

Alex Mentry had discovered oil in 1876 just to the south of the rancho (which became the Pico Canyon Oilfield), but the group of investors who sold to Newhall (25 cents per acre) had had no such luck.

McBean understood that agriculture alone was not going to pay the taxes, and that if the land was to be designated for residential homes, the company might as well head in that direction.

McBean retired soon after, hiring Stanford Business school graduates to manage the company while family members comprised all Board of Directors seats.

In 1971, the Newhall Land entered into a joint venture with SeaWorld Co. and opened the Magic Mountain amusement park, which was sold to Six Flags in 1979.

In 2004, the company was acquired by Lennar and LNR Corporation for approximately $1 billion, leaving Newhall Land and Farming owning 50% and Lennar and its industrial and commercial properties spinoff LNR owning the other 50% through a new holding company called LandSource Communities Development LLC.

[5] In early 2007, by a further transaction, Lennar and LNR each sold 34% interests in LandSource Communities Development LLC to a new set of investors, including the California Public Employees Retirement System.

In July 2009, LandSource Communities Development LLC and its subsidiaries emerged from bankruptcy under a new control structure with a new set of owners.