There are only five children of John Hart, Jr (John, Mary, Susannah, Sarah and Elizabeth).

John Hart Jr. was the son of John Hart (signer of the Declaration of Independence) and his wife Deborah Scudder. Please note: If you find a tree claiming John Hart, Jr. had a middle name (e.g. Roger or Mitchell), this is NOT the same John Hart, Jr. None of the Hart children were given middle names. The only John Jr. recognized by the DSDI or the DAR is the one married to Catherine Knowles. It would have been impossible for him to be the same John Jr as the ones with the middle names Roger or Mitchell.
John married Catherine Knowles and together they had one son (John) and four daughters (Mary, Susannah, Sarah, and Elizabeth).
**special notes, there are family trees online that claim Elijah Hart was a son but, in fact, Elijah was the son of another John Hart and his wife Hannah Phillips. Another untrue claim is that Mitchell Hart was a son but all evidence (including the wills of the John Hart and John Knowles) backs up John and Catherine only having one son. If any additional children show up on this FindAGrave page, they are NOT children of our John and Catherine.
Also, there is a FindAGrave page claiming that a "John Roger Hart" was the Signer's son. that claim is also untrue. John Roger Hart served in the Revolutionary War and the Signer's son John did not. JRH was born about five years after our John Hart, Jr.
More and more trees are popping up that John Hart, the Signer's son, was married to an Eleanor Campbell or Carroll with claims he was a bigamist*. This is a completely new rumor just recently created and wrong. There have been a number of descendants accepted by the Daughter's of the American Revolution and his marriage and children have been in the records for some time. There were numerous John Harts and the one married to Eleanor is very clearly a different John Hart. The DAR and DSDI only recognize Catherine Knowles as his wife.
Also both the 1890 and 1819 death dates are incorrect. Both dates are easily disproven. Please do not add either date to this page. Thank you.
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"John (2), son of John (1) Hart, "the signer," was born October 29, 1748. About the year 1770 he emigrated to Point Coupee, Louisiana, where he became wealthy in slaves and property, but was stripped of all by the Spanish authorities and confined eight months in prison with many others. He went to Cuba after his release, again became wealthy and again met reverses. He then returned to Hopewell, New Jersey, where he again amassed a good estate. But no son of John Hart, "the patriot," could be allowed to live in peaceful plenty. The British burned his buildings, destroyed his property and compelled him to remove. He sold all his large possessions, taking continental money in payment. This so depreciated in value that in his declining years he was left in poverty. He married Catherine Knowles, of Tacony, Pennsylvania. Children: Mary (of further mention) ; Susannah, married Joseph Hall, of Philadelphia; Elizabeth, married James Bowyer; Sarah, married William Reed, of Philadelphia; John, married Mary Shreeves, of Philadelphia." taken from Genealogical and family history of western New York: ...volume 2 by William Richard Cutter
Taken from the Cleon E. Hammond biography of John Hart, John Roger Hart was actually the son of John Hart's (the Signer) cousin, Richard Hart. The same biography states that there is quite a bit of misinformation about John, Jr. having served in the Revolutionary War when, in fact, he did not.
* For more on why this is not the John Hart married to Eleanor Carroll: http://whelangenealogy.blogspot.com/2018/08/the-curious-case-of-john-hart-jr-whose.html

There are only five children of John Hart, Jr (John, Mary, Susannah, Sarah and Elizabeth).

John Hart Jr. was the son of John Hart (signer of the Declaration of Independence) and his wife Deborah Scudder. Please note: If you find a tree claiming John Hart, Jr. had a middle name (e.g. Roger or Mitchell), this is NOT the same John Hart, Jr. None of the Hart children were given middle names. The only John Jr. recognized by the DSDI or the DAR is the one married to Catherine Knowles. It would have been impossible for him to be the same John Jr as the ones with the middle names Roger or Mitchell.
John married Catherine Knowles and together they had one son (John) and four daughters (Mary, Susannah, Sarah, and Elizabeth).
**special notes, there are family trees online that claim Elijah Hart was a son but, in fact, Elijah was the son of another John Hart and his wife Hannah Phillips. Another untrue claim is that Mitchell Hart was a son but all evidence (including the wills of the John Hart and John Knowles) backs up John and Catherine only having one son. If any additional children show up on this FindAGrave page, they are NOT children of our John and Catherine.
Also, there is a FindAGrave page claiming that a "John Roger Hart" was the Signer's son. that claim is also untrue. John Roger Hart served in the Revolutionary War and the Signer's son John did not. JRH was born about five years after our John Hart, Jr.
More and more trees are popping up that John Hart, the Signer's son, was married to an Eleanor Campbell or Carroll with claims he was a bigamist*. This is a completely new rumor just recently created and wrong. There have been a number of descendants accepted by the Daughter's of the American Revolution and his marriage and children have been in the records for some time. There were numerous John Harts and the one married to Eleanor is very clearly a different John Hart. The DAR and DSDI only recognize Catherine Knowles as his wife.
Also both the 1890 and 1819 death dates are incorrect. Both dates are easily disproven. Please do not add either date to this page. Thank you.
----------------------
"John (2), son of John (1) Hart, "the signer," was born October 29, 1748. About the year 1770 he emigrated to Point Coupee, Louisiana, where he became wealthy in slaves and property, but was stripped of all by the Spanish authorities and confined eight months in prison with many others. He went to Cuba after his release, again became wealthy and again met reverses. He then returned to Hopewell, New Jersey, where he again amassed a good estate. But no son of John Hart, "the patriot," could be allowed to live in peaceful plenty. The British burned his buildings, destroyed his property and compelled him to remove. He sold all his large possessions, taking continental money in payment. This so depreciated in value that in his declining years he was left in poverty. He married Catherine Knowles, of Tacony, Pennsylvania. Children: Mary (of further mention) ; Susannah, married Joseph Hall, of Philadelphia; Elizabeth, married James Bowyer; Sarah, married William Reed, of Philadelphia; John, married Mary Shreeves, of Philadelphia." taken from Genealogical and family history of western New York: ...volume 2 by William Richard Cutter
Taken from the Cleon E. Hammond biography of John Hart, John Roger Hart was actually the son of John Hart's (the Signer) cousin, Richard Hart. The same biography states that there is quite a bit of misinformation about John, Jr. having served in the Revolutionary War when, in fact, he did not.
* For more on why this is not the John Hart married to Eleanor Carroll: http://whelangenealogy.blogspot.com/2018/08/the-curious-case-of-john-hart-jr-whose.html