Critik asked:
> I can’t find anything on the net that would show buttons made by Lewis & Tomes. How can I find out what.
There is no book which shows brass 1-piece flatbuttons (like your find) made by Lewis & Tomes.
Since you don't seem to know:
However, there is a book which lists almost all the known backmarks made in the US, the Confederacy, and Britain. It is "American Military Button Makers And Dealers; Their Backmarks & Dates" by McGuinn & Bazelon.
Some possibilities from that book's listings:
L & T (as Spats said) Lewis & Tomes, located in Birmingham England with an office in NY City
L & Kendrick (Leavenworths & Kendrick), located in Waterbury CT
Because there seems to be a lot of space after the "L &" before you get to the end of "Gilt, I suspect it said L & Kendrick.
According to the McGuinn-&-Bazelon book, Leavenworths & Kendrick was in business from 1829-34. I should mention, after that time, brass 1-piece flatbuttons rapidly fell out of public favor due to the advent of INEXPENSIVE machine-made 2-piece brass buttons with "ornate" emblems on their front.
BTW, Spats is definitely correct, the rest of the backmark on your button said Double Gilt.