After a 10 year search I finally own a trademark stamp made in America. The stamp is the exact standard depth of Manchester stamps and the 8 inch wide design depicts the Mexican national emblem of an eagle stood on a cactus holding a snake. http://en.wikipedia.org/wiki/Coat_of_arms_of_Mexico 
The coat of arms changed over the years and this design, by José Mariano Torreblanca, was used from 1823-64 and then from 1867-93, so the stamp was made during one of these two periods. 
The stamp was made by J Cosgrove, Providence, R.I. and a Census lists a John Cosgrove working as a stencil cutter (The American term for a stamp maker) in Providence in 1880.
This is where things get interesting. The census lists John Cosgrove as being English, born in 1833 with an English father and an Irish mother.
His wife Sarah is listed as Irish and his 4 children were born in various places:
Matilda COSGROVE, 18, birthplace, Ireland
Albert E. COSGROVE, 17 birthplace, Ireland, Occupation: Stencil Cutter
Alice J. COSGROVE , 12, birthplace, Massachusetts
John COSGROVE, 8 birthplace, Rhode Island 
Searching for a John Cosgrove who was born in England in 1833…….
A John Cosgrove, born in Lancashire in 1833, was listed as living in Manchester’s Ancoats textile district in 1841 and 1861 censuses.
In 1880 the USA census states that his son and daughter was Irish and the youngest was 17, which means they must have moved to Ireland at some point.
They must have left for America before 1868 because his daughter Alice was born in Massachusetts.
There is a Thomas John Cosgrove who married a Sarah Mcmullon in 1859 (When John was 26) in Carnmoney, 7 miles from Belfast – the only ‘Sarah’ to marry a Cosgrove in that 20 year period. He is half Irish so he could have gone to Ireland to get married and moved there just after the 1861 Manchester census, having babies Matilda and Albert (in 1862 and 1863) in Ireland.
He probably learned his stampmaking trade in Manchester and then moved to Belfast. Between 1861-65 there was the “cotton famine” because of over production and a restriction where they couldn’t get cotton from America because of the civil war so many Manchester factories shut down, so it would make sense to move to Belfast where the Irish linen trade was based and much less affected. There were linen trademark labels so I am presuming there were Irish trademark stamps being made in Belfast too.
The alternative is that he married Sarah when she already had children born in Ireland and went straight from Manchester to America, though that seems unlikely as his children are all listed as having an Irish mother and English father.
They emigrated at some point after 1863 and had their daughter Alice in Massachusetts in 1868. The family then made their way to Providence, which was the centre of “Stencil cutting” in the Northeast.
It is interesting that Albert was following his father into the stampmaking trade.
So what this single stamp has showed is that there was a direct link between Manchester stampmakers and American Stencil cutters. The stamps are identical in dimension and construction techniques.
The reasons why John Cosgrove moved from Manchester to Providence via Ireland will probably never be known but putting his name on the side of this stamp for the Mexican market has revealed a wealth of information about the trade and the Cosgrove family history.
The stamp itself would have been made no later than 1893 because the Mexico coat of arms changed in that year but cannot have been made before 1868 because John Cosgrove lived in Ireland at that point.
If anyone wants to add any more information, such as finding information on John Cosgrove’s father, the date when the Cosgrove family emigrated to America, or what happened to the Cosgrove children, I would love to hear from you.
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I am the owner of 80 Dover Street Providence RI. John Cosgrove, built this house in 1877, it says that “Cosgrove manufactured copper stamps and stencils used by bleacheries and cotton and woolen mills to print fabrics”. Home is a second empire Victorian with slate mansard roof well appointed for the time. Is this the same John Cosgrove? House passed to Sarah Cosgrove then Phillip Conaty, father of John Conaty.
Hi Mary
It was so great to make this connection and I hope you enjoy the print I made from one of John Cosgrove’s stamps that you can hang in his original home