I may possibly have a connection to a Carroll family myself. The name occurs as a middle name in my MARTZ family, which was anglicised to MARCH.Peter Martz and his wife came to Markham, Ontario in 1813, from Montgomery County, New York and I have not yet been able to find out if there is a link to a Carroll family, but if so, they may well have been Loyalists. Have you found anything yet about your Carroll line?
I must say that it is rather a strange co-incidence, as well, that I have been involved in researching the family of another Stephen Sears, born in Kent, UK, in 1822, whose son Robert Sears was born in Toronto in 1859. I also have another Sears from Kent in my family tree, related by marriage - several of these Sears family members emigrated to the U.S. in the 1800's. Would your Sears family happen to be English?