Gershom Mendes Seixas was the first native-born rabbi in the United States. He was one of seven children of Rachel and Isaac Seixas. He was born in New York City on January 15, 1746. His father had emigrated from Lisbon, Portugal, to New York in 1730, where he went into the mercantile business.
Gershom Seixas studied with Rabbi Joseph Pinto. He was appointed to be the rabbi of Congregation Shearith Israel, a Spanish and Portuguese synagogue in New York City, in 1768. Seixas was the father of fifteen children from his first wife, Elkay Cohen, who died in 1785, and eleven by his second wife Hannah Manuel, whom he married on November 1, 1789.
Seixas also served the religious needs of other Jews in the outlying areas of New York. He was the teacher of Hebrew, literature and law for the community.
He and most of his congregation left New York City in 1776, when the British were approaching during the American Revolutionary War. He went to Stamford, Connecticut, while most of the congregation went to Philadelphia. Four years later, he joined the others in Philadelphia where he helped found a new synagogue, Mikveh Israel. He was its rabbi for two years.
He was the first rabbi in America to give his sermons in English. He gave sermons which dealt with Jewish participation in the life of the state and made appeals for support of the American Revolution and against the British-Indian raids in the Northwest Territory. When the council members of Philadelphia made eligibility for an assembly seat dependent on professing the divine origin of the New Testament, he and other Jews fought against this unconstitutional religious test.
