Our family always always knew him as Dennis. But then we found the census from 1900. Everyone is on it, but our "dennis" was reffered to as Francis-we don't know why.
Here is his family:
Parents: Elizabeth O'Connell & Michael Cahill (born January 1855-died young)
married 1885-both parents born in Ireland-both died young, leaving the boys without any parents.
Edward Cahill-born May 1889-lived in New York City, New York, New York-born there.
William Joseph Cahill (My great grandfather)born September 12-15?, 1895, New York City, New York, New York.-Served in the Navy, maybe Merchant Marines. Married Sophie Scozzafava Jan 21, 1921. Wiliam died 1952, Forrest Hills, NY. * I need to contact my family to get the date of William's birthday, but its between 9/12 and 9/15.
Francis Cahill "Dennis" born May 1895, New York City, New York, New York
Joseph Cahill b. January 1897 b. New York City, New York New York.-He served state side as a Military Police man.
Its hard to know that much about my great grandfather's brothers. Mike and Elizabeth died when the boys were young, maybe 1902? They were split up, and sent to different orphanages. My great grandfather (William Cahill) was sent to the Mercy Institution, in Tarrytown, NY.-He also spent time over seas, in Ireland; they didn't treat him well.-So, unfortunatley, I can't tell you any more information on anyone else, besides William Cahill.
After WW1 the brothers reunited-but prior to ww1, they didn't know where each other had gone.
I Hope this helps in finding at least someone. I was going to write to the Ny State Archives-but, now I don't if that will produce any data.