Appearing on flags and government buildings across the county, the emblem features the San Gabriel Mission which has a cross on it's roof.
The American Civil Liberties Union (ACLU) brought a law suit before US District Judge Christina Snyder who concluded the design "places the county's power, prestige and purse behind a single religion, Christianity."
Supporters of the current seal argued it was historically accurate and reflected the influence of Franciscan missionaries from Spain who settled in California.
According to the United States Mint, "In God we trust" is the country's official motto and it's appearance is mandatory on all coins and paper money.
The Pledge of Allegiance was changed in 1954 to include the words "under God" in the sentance: "I pledge allegiance to the flag of the United States of America, and to the republic for which it stands, one nation under God, indivisible, with liberty and justice for all," the ushistory.org website said.