SAMUEL MYER ISAACS was born in Holland in 1804 but as a child moved with his family to England, where he lived for the next twenty-five years. He had a respectable Jewish and general education, and achieved enough of a reputation in London to be invited to serve as cantor and preacher at the Ashkenazi B’nai Jeshurun Congregation in New York, which was eager to find a preacher with a strong command of the English language. He arrived in New York with his wife in 1839. In 1846 he became the leader of Congregation Shaaray Tefila, which broke away (apparently with some animosity) from B’nai Jeshurun over doctrinal issues. He remained at this congregation until his death in 1878. Isaacs introduced to New York the practice of regular sermons in English; in this he was apparently, among American Jewish leaders, second only to Isaac Leeser in Philadelphia.

In 1857 he founded, together with his three sons (some of whom shared the preaching responsibilities at the synagogue), the Jewish Messenger as a periodical that would express the religious and cultural values of a traditionalist Judaism seeking to define a position between that of the most radical reformers and the opposition in principle to any change at all. In addition to the various literary and historical writings by contemporary authors published in its pages, he frequently reproduced the texts of sermons, including his own, especially those he delivered on the Sabbath of Repentance.

Isaacs generally avoided politically charged controversy in the Messenger, steering clear of the vituperative controversy over the biblical justification for slavery that erupted at the beginning of 1861, and—like Isaac Mayer Wise— warning against the use of the pulpit to discuss political issues. Speaking of David Einhorn's need to flee for his safety from Baltimore to Philadelphia, he wrote, ‘It seems that he has been mistaking his vocation, and making the pulpit the vehicle for political invective … A Minister has enough to do, if he devotes himself to the welfare of his flock; he can afford to leave politics to others.’