Hi Cecjr51
I did look for the death of weaver Samuel Cummins/Cummings and did not find one. However if you have him in a Directory in Pennsylvania in 1786 then the weaver is definitely ruled out as his wife died in Yorkshire in 1787.
Also it does not seem credible that he married on September 12th 1786 in Yorkshire and arrived in the USA in time to get a listing in the Directory for 1786. Such publications were prepared months prior to the year they were published.
Samuel's modest grave marker shown on Find a Grave shows his first wife as Mary P. It seems even the person who placed the marker had no information about his first wife's full name. I would think that he was married in the U.S. rather than England.
There is a list of correspondents of the Rush Family held by the Library Company of Philadelphia. It seems Samuel wrote to a Rush family member in 1803 inquiring about medical lectures.
See:
http://www.lcpimages.org/lcpAT/pdf/RushBenjamin_alpha%20correspondence.pdfThe letter may hold some clues about his education and medical career. Also note that the Rush family includes a member called Benjamin Rush. Could he be Old Ben?
To me the name Maxwell suggests a Scottish connection. Have you considered looking for a birth there?
Good Luck with your search.
Venelow
Canada
P.S. I just Googled Benjamin Rush - physician and signer of the Declaration of Independence. He died in 1813.