The earliest record of a request for admission to the fold occurs in the minutes of Shearith Israel during the 1770s, when Benjamin Jacobs petitioned, apparently without success, to have his fiancée converted to Judaism. Some years later, in 1788, James Foster was refused admission; thereupon he applied for a letter of introduction to the rabbinical authorities in Amsterdam, whom he hoped to induce to admit him to the Jewish fold. Touchingly, Foster quoted Ruth's prayer to Naomi, "Entreat me not to leave you."

Although the prohibition against making proselytes had become part of the organic law of Shearith Israel in the eighteenth century, the newer immigrants, less burdened by colonial traditions, seem to have taken a different attitude. In the 1830s, several unauthorized conversions were made in the New York community; in at least two of these cases, the conversion was recognized as a fait accompli by Shearith Israel. The earliest of the newer synagogues soon adopted Shearith Israel's antagonistic attitude toward admission to Judaism; both Bnai Jeshurun and Anshe Chesed frowned on unauthorized conversions; in one case, Anshe Chesed refused on a mere technicality to recognize a proselyte.

Shaarey Zedek, however, in its early days, admitted to the fold a number of women who had married Jewish men. In April 1841, this congregation served notice:

"to all such whom it may concern who are members of this congregation and are married to women [sic] who are shelo begiyur that between Pesah and Shabuot facility will be given by the Trustees....to effect the same to wit: to enter such women and their children kadat unto the congregation of the Lord and that if any such who shall not enter and take advantage of such facility shall be excluded from this congregation and all such who plead that their wives have already been entered kadat to produce such certificates of the same or stand excluded from this congregation."

This action of Shaarey Zedek in direct opposition to the policy of the older synagogues aroused considerable protest from other Jews in the city. The membership of Bnai jeshurun, in meeting assembled, passed a resolution to investigate the alleged practice. In the face of this opposition, Shaarey Zedek became convinced that the admission of converts without proper rabbinical sanction was contrary to Jewish law; soon this congregation, too, adopted a resolution prohibiting the making of proselytes. While proselytism was at its height, however, a number of women were admitted to Judaism, and a new English word was coined to describe them; a woman convert to Judaism was now called a "Giyuristee."

When Max Lilienthal was elected to the rabbinate of the German Jewish community, he made several converts. This, of course, did not violate the policy of the new York synagogues, for Lilienthal was an ordained rabbi and could, therefore, admit proselytes. There seem to have been only three such cases. Two were children whose deceased father had been a Jew and whose Christian mother informed Lilienthal that her husband had desired that they be converted and brought up as Jews. The third was a woman who wished to marry a Jew; she was admitted to the fold by Lilienthal's Bet Din, which consisted of himself, Hermann Felsenheld and Isaac M. Wise.

The reform congregation, Temple Emanu-El, at least during the rabbinate of Samuel Adler, did not object to the admission of converts, provided that the board of trustees and the rabbi were convinced that the candidate had no ulterior motive, such as a desire to marry a Jew. The applicant was usually examined by the rabbi; he then signed a statement which was presented to the board of trustees. The statement attested that the applicant desired to embrace Judaism from purely lofty motives. The board thereupon granted permission for the conversion and the rabbi instructed the neophyte in the tenets of Judaism. When the candidate had completed the course, he was admitted to Judaism in a ceremony previously unknown in the city of New York. The proselyte appeared at the temple on a Sabbath and, at the conclusion of the service, came forward to the pulpit. The minister again asked him, as he had at the original interview, whether the candidate wished to become a Jew only from a firm desire to know and practice Judaism. Giving an affirmative answer, the convert made confession That the Lord was the only God, that He created man that He revealed His law unto Moses and the prophets; this was followed by a promise to live according to Jewish belief, and by the recital of the Shema in both Hebrew and English. The minister then admonished the proselyte to observe the Sabbath and holy days, to recite the Shema morning and evening, and to live in virtue and truth. To conclude the ceremony, the minister pronounced the priestly blessing, placing his hands on the convert's head. Emanu-El accepted only a few converts prior to 1860.

The prohibition against the making of proselytes was in force at most New York congregations. If the attitude of the leading synagogues had been more lenient, and if these synagogues had provided proper rabbinical supervision, many of those Gentiles in the community who married Jews might have sought admission to the fold. It is quite possible that the difficulties placed in the path of would-be proselytes to Judaism in New York City tended to increase the number of intermarriages.

One point at which it is possible to trace the growing laxity in the observance of religious law is in the periodic visits of the Jewish women of New York to ritual baths. In a community like that of New York provisions for the observance of this law had to be made by the synagogues. In the earliest days, the women of Shearith Israel made use of a natural spring near the synagogue for these ritual purposes. By 1759 Shearith Israel built a mikvah on its grounds, adjacent to the Mill Street synagogue. In its later locations, this congregation did not install ritual pools; the women, apparently, had to use the pools of other congregations or neglect the law. Bnai Jeshurun did not build a pool of its own until 1833, after the close of the Mill Street Mikvah. In the early 1850s, Shaarey Zedek built a pool in its Henry Street synagogue, and Anshe Chesed built one in its Norfolk Street synagogue, which was, in its day, the most important in the city. Thus new York City always had one or more pools to which Jewish Women could go for ritual purposes, the women of one congregation using, where necessary, the facilities of another. It was customary for the ritual pools of the city to be under the direct supervision of the wives of the sextons of the synagogues.

Since matters of ritual of this nature are rarely mentioned in the sources, it is not known how widespread was the practice of visiting these pools. Using the income of the Anshe Chesed pool for seven months in the year 1851 as our basis, we may assume that some 200 women repaired to the New York ritual pools each month. At this time, the number of Jewish families in the city may be estimated at 4,000. We are on surer ground when we assume that ritual practice of this sort had declined among the native Jews and that it flourished only among the more recent immigrants. The mere fact that Shearith Israel did not find it necessary to install a pool in its Crosby Street synagogue is sufficient indication that this ritual had ceased to be significant among the wives of members of this ancient synagogue.