Hi, my name is Sherri Klish and I am a descendent of Wlliam Costigan and Maria Gaheney Costigan. They are my great great grandparents on my mother's side. Their daughter Maryann Costigan married Peter Conway. One of their sons was Nicholas who was my Pop-Pop. Have you been able to find anything out since your post? If you did, maybe you can share some information. Looking forward to hearing from you. Thanks!
Sherri Klish
sklish@comcst.net