Having reviewed Jewish tradition and history, we can surmise with a decent level of certainty that Isaac Marks pretty much maintained a practice in medicine with some parts of his philosophy kept private for much the same reason he kept quiet about his true thinking about Jesus and Christianity.   By concealing this part of his persona, he was able to perform more favorably and successfully within local social settings.  This demonstrate the tolerance that existed in the rural parts of New York, which the urban centers may have lacked at times.  Even though he was Jewish, Isaac was not Sephardic like most of the Jewish people residing in New York City.

This minor cultural difference did not completely prevent people from the other Jewish culture from including him into many of their community and religious ventures.  The fact that a group of 10 men was required in order for certain ceremonies to be performed, like the frequent brisses that were requested, meant that Isaac had to be included in the my broader sense of a Jewish community.  Much of the medicine Isaac practiced would not have been too different from the practices engaged in by Sephardic doctors, should there be one or two in the nearby regions.  Thus his skills as a physician had an importance that outranked any social or personal claims made by members of other Jewish communities  regarding his ability to be included in traditional Jewish events.

Dr. Isaac Marks

The first evidence for Isaac Marks’ residency in the Dutchess County is found in the  tax records for the Rombout Precinct from 1743 to 1745.  Additional evidence was found in  a local ledger for the same precinct in Dutchess County.  On October 16, 1745,  “To Doctor Marks 12/” was entered, with a note referring to the Court of General Sessions identifying this transaction as a Payment made out to Dr. Marks for care of the poor.  Two years later, on April 10, 1747, the details about a boundary marker produced for the local tax records made mention of “the Jew Doctor’s House.”  In 1748, a Deed notes “the Jewish Doctor” as a neighbor.   Little more is mentioned of Isaac Marks again, until October 1756, when the Court ordered a payment be made “to Marks and Osborn for attendance and drugs” for British Foot Soldier John Lane.

This evidence leaves us with no doubt about the fact that Isaac Marks was both Jewish and a Doctor.

One historian’s added a personal note to a similar recount he made about the Jewish Doctor, suggesting he may also be referred to as a “French Doctor”, a conclusion he drew based on his analysis of the placement of these events locally with regard to time.  He adds that Isaac Marks was documented as living along King’s Highway (now called Market Street), adjacent to where the current Adriance Library facility now stands [see, p. 16, his text.]  Continuing this logic, from 1743 to 1748 Isaac Marks was in the Rombout Precinct, but afterwards removed to Poughkeepsie.

This leads me to ask:   Was Isaac Mark’s Poughkeepsie residence like, adjacent to, or the same as Osborn’s residence?  Did they exchange houses due to changes in family size?  Since they worked together, was their bondage such that this was a comfortable option for each of them?  Was Isaac the doctor who dealt with the local witches or Mother Ann Lee during their stays in jail?

Another interesting part of Isaac Marks’ social history shows us he was a devoted Jewish leader, adhering to many of the same human rights issues that have foreever been a major part of the life of Jewish leaders.  There is additional evidence in the county records that Dr. Marques felt a sympathy for African slaves or servants.  As a Jew, Isaac Marks was well aware of what the end results of fear and prejudice could be.  He, like other Jews, knew the local oral histories being told about how the Sephardic Jews who removed from Brazil to New Amsterdam were susceptible to public ridicule soonafter settling in New York and Newtown, Rhode Island.   It is commonly said by Jewish writers that the high degree of tolerance Jews had for this kind of prejudice is what kept them alive.  The reason for Isaac Mark’s familiarity with this type of social injustice based on race is simple.  Isaac Marks may have bore a dark complexion, a characteristic expected if he were of Sephardic, but Isaac was instead Ashkenazi and not of Middle Eastern decent, but rather had a Central to North European, he did not stand out as much as his comrades.  To them, he may not have experienced what the Sepharics considered to be “a complete Jewish life.”  Isaac suffered less that others as a part of the Jewish diaspora.

For a recent example of this problem with racial discrimination, consider the recent history of Jews in South America.   In Brazil, the Jews were side by side with those bearing both fair and dark complexions.  Some bore a complexion close to that of Africans, and others of Spanish Sephardic origin resembled the Melanos later imported to North America and sold as slaves.  Other types of prejudice like this were of Sephardic origin.  Haym Solomon of New Amsterdam/New York City had slaves, and after one escaped, put an advertisement in the local newspaper to get him back.  Native Americans in some cases lived with European settlers where they served as slaves, and even people from India in some cases made it to Great Britain for their later sale as servants (Catherine Filipse, of Phillips patent history in Westchester County).

Jews in Brazil and North America, like Isaac Marks, no doubt felt a respect for Brazilians and others who were excommunicated by their churches, forced into accepting Christian faith by swearing on Moses books, to avoid a forced deportation from their native lands threatened to them by local government members.  This led many of the Jews to become Christians in a physical sense, by looks and by dress, but remain Jewish in a more spiritual sense.  Throughout New England, New York, and Pennsylvania, many of these unique cultural groups formed little communities in which to practice and abide by their traditions. Such was the case for the German Presbyterian town of Rhine-beck and the Huguenot village of New Paltz.

When Jews migrated into these new cultural settings, it is possible they took advantage of this opportunity to redefine themselves.  Living near New Spain they took on Hispanic surnames.  Living in New York but serving as merchants to New Spain, many of these merchants also took on Hispanic names.  Near New France, within the Huguenot territory of Hudson Valley,  they took on French names. In German Rhineland territory, they took on German names. In New England and British-controlled regions, they names became Anglican in nature.   So, for Isaac, he could be Isaac Marques, Isaac de la Marques/Marquis, Isaac Marx, or Isaac Marks.

Along the Hudson River Valley, those regions through which the King’s Highway was laid were claimed by the Dutch.  Isaac Marks might have removed there from Amsterdam, or, if a local, from New York City, with the hopes of avoiding scrutiny and prejudice due to his Jewishness.  In the more suburban and rural regions along the Hudson River where he took up a new practice, he may have begun to prosper even more on lands that he had purchased using his earnings as a merchant with New Spain while residing in New York.

We see Isaac Mark’s sympathy with the Africans brought to this country by what he possibly did to retain their faith and rejuvenate their hope for freedom from bondage and slavery.

Ancient Document 3584 at the Historical Society is an example of this humane gesture on behalf of Isaac’s family.  In it, according to a recount by historian Frank J. Doherty, is a tale of three negros who were arrested by the constable after stopping at a “French Doctor’s” house in Dutchess County.  The doctor’s mother-in-law prepared for them “cyder’ made from unknown additives and materials.  This imbibation intoxicated them leading to unruly conduct “two stops later” in the nearby hills.  (What ensued is uncertain as of this point).

The Historian’s added note on this recount is most important.  He came to discover that the French Doctor and the Jew Doctor are the same, by analyzing the placement of these events.  According to Doherty, Isaac Marks lived along King’s Highway (now called Market Street) adjacent to the Adriance Library facility [see. p. 16, his text.]  Continuing his logic, from 1743 to 1748 ISaac Marks was in the Rombout Precinct and after removed to Poughkeepsie.

According to Daniels, it was the Sephardics who not only had control of the living manners, buit who also controlled the synagogues until 1816.  This separation of Jewish groups led to a division between the Ashkenazim and Sephardim, and so those who inhabited the urban areas were pretty much Spehardim as was the case in Holland and London; the Ashkenazim on the other hand tended to move about, changing thier names when needed to fit into the new masses surrounding them.  At least until 1720, Ashkenazim were outnumbered by Sephardim.

During the late 1600s, the Jews built their homes in New Amsterdam on Whitehall Street, moving to Mill Street once the British regained control of “Nieuw Amsterdam” and renamed in “New York.” The Jews in New York city maintained their social, religious and political composure by building their synagogue here, and thus continued practicing their faith and holding the merchantile businesses together.

For the most part, early Jews got along with non-Jews in North America.  Many of them simply blended in with the social and political systems by changing the spelling of their names and by prudently practicing their religious and healing faiths.  The Sephardim, out of no choice of their own, often interacted socially with the Ashkenazim who later migrated there, and even intermarried at times due to lack of spouses from each of their sects.  Sephardic ladies also married into Dutch and English Gentiles, a behavior which was less often the case for Ashkenazis.  This intermarriage in turn increased the likelihood for success on behalf of the earlu North American Sephardic families, and left the Ashkenazis to live a life in the outskirts of the city.

The chief sign of this early politicking came in the choice of surnames by Jews.  In his early years, while interacting with the traders in New Spain, Isacc de la Marques could become Isaac Marquez, nearing the same names as several well-known hispanic Jews who were at work as free-traders in New Amsterdam/New York.  When Isaac later chose to interact with Huguenots along the Hudson River Valley, he used his normal surname “de la Marques.”  A few years later, Isaac may have also become the “Germon Isaac” referred to in Dutch Reformed Church records (this is a much less likely name change however), and finally, during his last twenty years of his life, soon after his removal to the Dutch-English counties of Orange and Dutchess, Isaac Anglicized his name to make it Isaac Marks.

It was during this time frame that he instructed and worked alongside young Dr. Cornelius Osborn.


Doris Groshen Daniels. “Colonial Jewry: Religion, Domestic and Social Relations”  (American Jewish Historical Quarterly, March 1977 (Vol. 66, no. 3)

Leo Hershkowitz in “Some Aspects of the New York Jewish Merchant and Community, 1654-1820. American Jewish Historical Quarterly, January 1977, Vol. 66, no. 1, pp. 10-11, and September 1976, p. 10-34.,

Including “Isaac Rodrigues” on 6 July 1723 [Isaac Rodriguez Marks? Possibly not.  See Heschkowitz, p. 17, fn 30, for both “Isaac Rodrigues” and “Isaac Raphael Rodriguez”.

Treatment of Francis Filkin’s son?  Taken from General Sessions Book, noted in Reynolds, Helen Wilkinson.  “Physicians and Medicine in Dutchess County in the Eighteenth Century.”  Yearbook of the Dutchess County Historial Society, pp. 78-88. [year?]  p. 79.

Rombout Precinct land changed hands.  See boundary description in which his name appears.  Deeds, vol. 9, p. 81.  Reynolds, Helen Wilkinson.  “Physicians and Medicine in Dutchess County in the Eighteenth Century.”  Yearbook of the Dutchess County Historial Society, pp. 78-88. [year?]  p. 79.

Could Isaac still have owned this land?  Was he living there?

General Sessions Book.  From Reynolds, Helen Wilkinson.  “Physicians and Medicine in Dutchess County in the Eighteenth Century.”  Yearbook of the Dutchess County Historical Society, pp. 78-88. [year?]  p. 79.


The following are hard to find articles on medicine and Jewry.

Feel free to download, copy, etc.

On the state of Medical Art among Jews as recorded in the Bible by Walker 1830

The sanitary and dietetic Laws of the Hebrews as related to medicine by Blumenthal 1859

Moses as a sanitarian by Williams 1882

The plagues and pestilences of the Old Testament by Bombaugh 1893

The Jews in medicine by Ullman 1898

The Jews in Medicine by Schreiber1902