Thomas Eustis ( Eustace, Huestes) was born in about 1822-24 probably in County Longford, Ireland. He was the oldest of eleven or twelve children born to the family of Patrick Eustace. His mother probably was Catherine Cunningham although no birth or baptism records are available to confirm this. Thomas spent his boyhood in Townland Collum in the Parish of Cashel. While nothing is known about his childhood, we do know that the Cholera outbreak of 1832 and the Great Famine of 1845-49 occurred during his early years in Ireland. He obviously survived both.

There is substantial evidence that during April 1850, Thomas together with his sister Bridget and their cousin John (also called Daniel) Eustace/Eustice of Ballymahon, Shrule Parish departed from Limerick on the Polly, a 281 tonne ship. (The Polly was a ship type called a snow rig which was similar to a brig.) They arrived in New York City on May 18, 1850. John and Bridget immediately went to Schuylerville, Saratoga County, New York to join relatives and other Irish immigrants from the Parishes of Cashel and Shrule, County Longford. Among those at Schuylerville was Bridget Eustace Carle/Carroll and John Eustace, brother and sister to Patrick Eustace, father of Thomas and Bridget and James Eustace, father of John. Although Bridget and John Eustace apparently went directly to Schuylerville and appear on the 1850 US census of Schuylerville living with the William and Bridget Carle (Carroll) family, Thomas may have gone elsewhere at first. He first appears as Thomas Ustis, age 24, servant in the home of Mayo Pond on the 1855 New York State census of Schuylerville. Mayo Pond was a prominent Schuylerville resident who served as town supervisor in 1845. Thomas became a US citizen at Schuylerville on September 22, 1858. His name is spelled Hustis on the application. Witnesses to the naturalization were Peter J. Dowling and John M. Lawton. Thomas signed with an X.

About 1859, Thomas married Bridget FitzPatrick, daughter of Dennis and Joanna FitzPatrick, natives of County Tipperary, Ireland. The couple is listed on the 1860 US census under the name Heustis, living at Schuylerville. The census taker reported that Thomas could not read or write. Thomas and Bridget are both listed as 35 years old. They had a seven month old daughter named Katy also listed on the census. On 1865 New York census, Thomas Eustice, age 35 and his wife Bridget, age 30 are listed in the Town of Saratoga. Thomas is described as a laborer and stated that he was a naturalized citizen. No children are present in the home. Their daughter Katie had died in July 1864 and a second daughter Julia had died a year earlier in 1863. Both are buried in marked graves at Victory Cemetery. In 1870, Thomas and Bridget Huestes were living at Quaker Springs, Town of Saratoga. He was working in the cotton mill and gave his age as 40 years. Bridget was listed as 33 years old. Also in the home were their sons Patrick and Thomas as well as Catherine Carroll, age 15, who was working in the cotton mill. Catherine was Thomas’s niece, the daughter of Bridget Eustace and William Carroll. Catherine’s mother had died in 1868; her father died in 1856. Next door to Thomas and Bridget was the Quigley family, Barney, age 76 and his wife Margaret, age 65, and their sons Patrick, age 25 and James, age 23. The Quigley’s son Thomas was the widower of Bridget Eustis, sister of Thomas, who died May 1, 1868.