Duffy Insurance Agency has acquired The Cowan Insurance Agency, a Haverhill-based firm established in 1938, enhancing its reach in Essex County, Massachusetts. The deal, described as a means to expand product offerings for Cowan’s customers, is part of Duffy’s broader growth strategy through acquisitions, which includes several other agencies across the state. Cowan Insurance, now led by fourth-generation owner Stefanie Guillemette, specializes in both personal and commercial insurance lines. Financial terms of the transaction were not disclosed.