Sant Teja Singh founded the Pacific Coast Khalsa Diwan Society in 1912 for the purpose of establishing a permanent Sikh settlement in the USA. Stockton Gurdwara was the result. Prayers first commenced at the Gurdwara grounds on October 24, 1912. 
“Sikhs Honor Rich History in Stockton,” The Stockton Record, September 22, 2012:
“The temple, at the far end of South Grant Street, also is home to thousands of Sikhs on the West Coast. For them, it represents an almost-mystical place deserving of pilgrimage, reverence and historical study. This fall, Stockton Gurdwara Sahib celebrates a century of history, some of it surprising: » It is oldest temple in the United States; the birthplace of Sikhism in America. » It has a direct link to Indian independence and was home to the Ghadar (Revolution) Party, which agitated for a free, independent and united India four decades before that status was achieved in 1950. Sikhs describe Stockton as ‘ground zero for India’s independence struggle.’ » America’s first Punjabi-language newspaper was published by the Ghadar Party and financed by Stockton Sikhs. » Bhagar Singh Thind, a civil rights pioneer and the first Sikh to serve in the U.S. Army (during World War I), was a member of Stockton Gurdwara. » Starting in 1957, Democrat Dalip Singh Saund served three terms in the House of Representatives. He was the first Asian, Indian and Sikh elected to Congress. Before that, he was secretary of Stockton Gurdwara. For many, the compound on South Grant – which will be renamed Sikh Temple Street on Jan. 1 – is hallowed ground.” – – – Read the rest here.
100 Years of Sikhs in the USA 