From local newspaper's timeline:
1953 - Ford Motor Co. announces plans for a new 160-acre, $50 million-dollar assembly plant employing 4,000 in unincorporated Milpitas. The plant opens in 1955 and will produce such cars as the ill-fated Edsel, the popular Mustang, the subcompacts such as the Pinto, Comet, Falcon and Escort, and pickups. The factory closes in 1983 after producing 4.7 million vehicles.
1954 - In an effort to stave off annexation by San Jose, the community votes to incorporate Jan. 26, 1954.
Construction of four new subdivisions begins: Sunnyhills, Milford Village, Sylvan Gardens and Milpitas Manor. To accommodate the housing needs of Ford’s multiracial workforce, Sunnyhills becomes a model of residential development.
New business construction boom on Main Street: bank, appliance store, medical center and restaurant.
1961 - San Jose’s efforts to incorporate Milpitas is soundly defeated at the polls by a vote of 1,571 to 395. The 1776 Minutemen symbol adopted by the anti-incorporation movement will become the city seal.
1962 - The community’s early ethnic and racial diversity will be reflected in the election of public officials. Milpitas elects Ben Gross, one of the first African-American city council members in the county. Gross will also serve as mayor.
https://www.mercurynews.com/2007/02/06/milpitas-a-look-back/