Hi Joanne I have searched for a marriage in Ireland, UK and USA from 1854 to 1864 to no avail on two subscription sites. Now you are in Troy I think and about 2 years ago I was in contact with a lady from Troy, she did no now live there and has recently passed on, in searching if my memory is correct there was an issue with Troy records not being released for some parishes, would need to Google again to see so maybe the marriage is there somewhere, if Bridgit is in the US by 1860 she was only 22 so unlikely to have married before departure. Do any of the available census online have a question on the number of years married which can assist.
I searched online for a Bridget McCormick and variants on the US shipping lists, between 1850 and 1860 born in 1838 plus or minus one I got 12 hits, not all going to New York, some only have transcription of name and ship etc, others youcan view the page of the mainifest, I was checking to see if Bridgit travelled with anyone in the known family, one likely one was travelling with a Mary Ann, you Mary her sister was only christened Mary as per register so maybe, ages ok. Another was travelling with a Catherine age 11 I think in 1857, another was alone but a number of Cunninghams, looked like a family were on the displayed page, all only said Ireland as place of origin, of course they could ahve arrived prior to 1850 which I have not checked but will try soon.
On my own family line I was trying for 12 years for a marriage not helped by having the wrong wifes place of origin, she had a loose relationship with her age, gave it 6 years younger on her marriage, age 5 years in the spaceof 10 and I cannot blame her for her death cert. she was 12 years out. At least you have firm birthdates.
Regards
Pat