As marsh land covered in sloughs, Brewer Island appears in United States Geological Survey (USGS) maps dating to 1892 (the earliest available for the area).

[9]: 37  While California was inhabited by humans as early as the 10th millennium BC, evidence of such habitation has not been found on Brewer Island.

[6]: 9 [10] Brewer Island was created in the late 1800s by Arthur L. Whitney and E. B. Pond, who built a series of levees around the salt marsh to reclaim the land for agricultural use.

In 1912, however, numerous parties entered protests to the San Mateo County Board of Supervisors, urging them to deny it a permit.

"[15] The argument in favor of using Brewer Island was that it could be used immediately, as the Alameda site "would require an enormous amount of fill before it could be improved for aviation purposes".

"[16] In August, the Times reported that "members of the military affairs committee of the house of representatives are on their way to the bay region from Cuba to make an inspection of Brewer Island and other sites proposed", for a base estimated to cost $5,000,000 ($88.7 million in 2023).

[13] San Mateo County again offered Brewer Island as a potential military site in 1935; this time as a seaplane base.

[20] Ultimately, the Civil Aeronautics Administration engineer forbade the use of Brewer Island, determining that aircraft approaches would interfere with safe operation of radio facilities.

[21][22] In 1952, the city of San Mateo conducted a study of the viability of Brewer Island for residential and industrial development,[23] but the land remained undeveloped.

[13] In the later half of 1954, the development of Brewer Island was proposed yet again; this time, it was part of a bayside expansion plan for the city of San Mateo.

[28] By August 26, a Citizens' Pro-Industry Committee, composed of several "civic, service, and improvement club leaders", had been organized to protest the development of homes on the island.

[13] Development would require large amounts of fill dirt to raise the land, taken from hills to the west of San Mateo.

[23] In 1958, the city of San Mateo's master plan included a "water sports center" on Brewer Island, consisting of a "system of inland waterways along the bayshore" developed from existing sloughs.

[37] This plan would have included "a hotel-inn, auditorium, baseball park, stadium, marina, horse show arena, central plaza, western town, stables and corrals, stockade museum, zoo, miniature working ranch [...] heliport, Indian village and museum, mock gold mine and museum, picnic and camp sites, Junior league baseball parks, tennis club, golf course, polo field, Country club, beach and trap shooting" as well as "permanent international displays of Mexico, Copenhagen, the Middle East, Hawaii, South America, Holland, Venice, France, Japan and England".

[42] The transaction involved developer Richard Grant and financier T. Jack Foster, who proposed a $350,000,000 ($3.6 billion in 2023) "self-supporting, balanced community of industry, apartments, businesses, schools, recreational facilities and homes for an estimated 45,000 residents".

[42] Also planned were "a championship golf course, a beach, a yacht harbor, theatres, public swimming pools, parks and playgrounds" in addition to "a community center, libraries, medical buildings, churches, shopping facilities and adequate parking" and a "small-size 'Radio City' for offices, recording studios, and TV production".

This involved dredging around 22,000,000 cu yd (17,000,000 m3) of sand from San Francisco Bay for fill, raising land on the island by as much as 6 ft (1.8 m).

[6]: 22 The population of Foster City, according to the 2020 United States Census, was 33,805;[49] corporations located there include Gilead Sciences[50] and Visa.