Cornelius was the son of John Phelan and Mary Phelan. Dr. Cornelius J. F. R. Phelan ( married Elidianne Gendron) was born in the parish of St. Colomban, County of Two Mountains, P.Q., May 10,1840, and received a classical education at the College of Ste. Therese. Leaving this institution, he entered the Medical Faculty of McGill University, from which he graduated with the degree of M.D., C.M., in 1865. During the College vacation of 1864, he visited the hospitals of the United States in order to perfect his knowledge of surgery. After graduating from McGill, he received his license from the Board of Physicians and Surgeons, and commenced practice at Knowlton, Que., where he remained till 1870. In January of that year he came to Waterloo, and at once established a large practice. Dr. Phelan is a studious man, of quiet habits and gentlemanly demeanour, and by rare devotion to his profession has won the esteem and confidence of a large circle of friends. He has been very successful, and is often consulted by his fellow practitioners in difficult cases. According to Father Forget of St. Columban, his daughter, Berthe Phelan was an extremely gifted woman, she married Louis Arthur Lessard in Waterloo (St. Bernardin church) June 1, 1897.
The above brief bio is from "The History of Shefford" by C. Thomas. (1877)
Another Phelan marriage was that of James Phelan, son of Martin Phelan and Mary Casey also of St. Colomban Parish, he married Bridget McGuirk, June 4, 1894 at St. Joachim de Shefford.