I have been doing research for 20 years.Most of the families are located in the Morris County region of New Jersey.
Bartholomew W. Dempsey came over in the 1850's and fought for the Union in the New Jersey 7th and was one of the first town marshalls. Other names in the tree include Cliffords, Smith, and Kennedy on my father's side.
Gannons came over in 1890 from England/Ireland and the Rodlers in the 1850's from Bavaria, Germany.Other names on my mother's side was Higgins, and Morrison who were early police.
I would love to do more research but I have hit the wall and need some more help.