The following email was received from Edward’s grandson: "Someone had a conversation with my grandfather (Edward Milligan) back about 1970. It has a family bracket drawn out that has on top John Oliver Milligan (Dublin, Ireland) & Nancy Davis (Summerville, SC) which isn't too far from Charleston, SC.  Under their name they had six children: Jewel ?; Mark, died in childhood; Joseph; Lillian, who married William Baker and she died 2/7/25 and they had 12 children. Edward Milligan (my grandfather) and John (died 1917). John Oliver Milligan came from Ireland in about 1845 with 3 brothers and 2 sisters to work on the PRR, as Maintenance of Way employees, when PRR was building a line from Philadelphia to Pittsburgh, PA.  They escaped their indenture to the PRR, and settled in the South. Their names and last known facts are as noted: William-to Andalusia, AL; Biddle-to Florence, SC; 3rd brother (name not known) was killed in the Civil War serving in SC regiment of CSA; Boren-married and settled in Charleston, SC; Betty-married a Capt. Reeves of Conway, SC. John Oliver ran a trading post above Charleston. John and his wife used sail boats to transport good from the post to Charleston (hides & furs to exchange for sugar, salt, etc.) Edward Milligan was a dental technician; Lillian was his grandmother. I have a death certificate that showed the death of Mary Jane Milligan (my grandfather's mother; actually Nancy Jane) as 3/13/1903 in Charleston, SC."
My research into why reference was made to, "They escaped their indenture to the PRR" led me to interesting facts regarding indentured servants.  An indentured servant is someone who signed a contract with someone in the U.S. and agreed to work for them in exchange for their passage way to America.  It was a very common practice in this era for people of many countries to come to American as indentured servants. Many of these individuals escaped from their commitments, often due to harsh work conditions, and rewards were usually offered for their return. If this does turn out to be the case, these Milligans seemed to already be settled in South Carolina since the early 1800's, much earlier than the above stated 1845. If you should find any records confirming this story, I would greatly appreciate your help. To date, records don't seem to connect to Ireland until possibly several generations prior.  All other census records indicate that Edward's father was born in SC. The 1900 US census shows Edward living with his parents, John O. Milligan and Nancy J. Milligan, in Mount Pleasant, Charleston, SC, USA; 1920 US census shows Edward and Lillian living in Charleston Ward 9, Charleston, SC. Edward reported that he was born in SC, and that both of his parents were born in SC. The 1930 US census shows Edward and Lillian living in Savannah, Chatham County, GA. It states that Edward's father was born in Ireland and mother was born in GA.  The children were listed as Clark and Oliver, so evidently they went by their middles names at times. The Social Security Death Index shows the last residence for Edward was Charleston, SC and that he died Feb. 1978.
I offer this information as a lead solely for those who are researching these family lines.