On 22 February 1767 , he married Margaret Mansfield , daughter of Samuel Mansfield , the sheriff of New Haven , an acquaintance that may have been made through the membership of both Mansfield and Arnold in the local Masonic Lodge . On February 22 , 1767 , he married Margaret Mansfield , daughter of Samuel Mansfield , the sheriff of New Haven , an acquaintance that may have been made through the membership of both Mansfield and Arnold in the local Masonic Lodge .