Barsimson had been sent out by the Jewish leaders of Amsterdam, Dutch Republic to determine the possibilities of an extensive Jewish immigration to New Amsterdam. With the fall of Dutch Brazil, it was imperative for Jews planning to leave Europe to find other new homes. He arrived at that port on the ship Pear Tree on August 22, 1654, having left the Netherlands on July 8. Barsimson was succeeded by a party of 23 Jews, who arrived at New Amsterdam in September, from Recife, Brazil, and established the first Jewish settlement in what would become the United States.
In 1658, Barsimson succeeded in securing from the Dutch municipal court in New Amsterdam a ruling which is surprising even in the light of latter-day principles of religious liberty. He was summoned to court as defendant on a Saturday; but the court decided, in the terse language of the record, that, "though defendant is absent, yet no default is entered against him, as he was summoned on his Sabbath." Three years earlier, Barsimson and another early Jewish settler, Asser Levy, joined in a petition to the governor and council of New Netherland to be permitted to stand guard like the other burghers, or to be relieved from the special tax imposed upon their nation in lieu thereof by resolution of governor and council; but their request was curtly refused, with the remark that they might go elsewhere if they liked. Instead of following this latter advice, Barsimson and other early American Jews succeeded before long in obtaining instructions to Governor Stuyvesant from his superiors—the Dutch West India Company of Holland—condemning such unjustified and illiberal discriminations.