Charles McGonigle was born on 16 March 1941 in Denver, Colorado to Thomas C. McGonigle and Elizabeth Eckert. Within a few years his parents divorced and his father remarried Elva Barksdale. Thomas was raised by his father and stepmother in Denver where he attended Cathedral, Saint Louis, and Loyola Grade Schools, and Saint Francis de Sales High School. He continued his education at Loras College in Dubuque, Iowa from 1959-61.

Father McGonigle entered the novitiate for the Dominicans, Province of Saint Albert the Great at Saint Peter Martyr Priory, Winona, Minnesota, on 30 August 1961 and received the religious name, Declan. He professed his first vows on 31 August 1962 at Saint Peter Martyr Priory. He continued his studies for the priesthood at Aquinas Institute of Theology in River Forest, Illinois then in Dubuque, Iowa. He professed his solemn vows on 31 August 1965 and was ordained to the priesthood on 25 May 1968 at Saint Rose Priory in Dubuque. He furthered his studies after ordination at The Divinity School, Harvard University, earning a Master of Arts in Theology in 1969 and a Doctor of Theology in Church History in 1976.

Father McGonigle was a teacher and administrator in the following institutions: Aquinas Institute of Theology (1970-81 [fourth President of the Institute from 1978-81]); Wartburg Lutheran Seminary (1981-85 [when Aquinas Institute moved from Dubuque to Saint Louis, Missouri, Fr. McGonigle became Chaplain at Saint Clara Convent, the Dominican Motherhouse in Sinsinawa, Wisconsin, and Adjunct Professor at Wartburg Theological

Seminary and the University of Dubuque]); Providence College (1985-87 & 1993-2010 [Academic Vice President and Professor]); Notre Dame University (Summers of 1986, 1988, & 1990); Catholic Theological Union, Chicago (1987-1993 [Vice President, Academic Dean, and Associate Professor of Spirituality). Father McGonigle served as a member of the Provincial Council and the Intellectual Life Commission and was named the Province's Regent of Studies in 1990.

Father McGonigle moved to Saint Thomas Aquinas Priory in River Forest, Illinois in June 2010 from Providence College due to increasing memory loss making teaching more difficult. A year and a half later he was transferred to the Assisted Living Center at Saint Pius Priory in Chicago. He remained there and continued to experience memory loss until the time he had to be moved to a more secure environment. He was admitted to the Resurrection Life Center in Chicago in the Spring of 2015. His dementia eventually took his life. He died on 4 August 2015 at the Resurrection Nursing and Rehabilitation Center in Park Ridge, Illinois.

Father McGonigle is survived by a half-brother, Paul Coons, and half-sister, Vickie Coons of Canton, Ohio. Services were held at Saint Vincent Ferrer Church in River Forest, Illinois, on Thursday, 13 August 2015. Mass of Christian Burial began at 10:00AM preceded by Sung Morning Prayer at 9:00AM. Father James V. Marchionda, O.P., Prior Provincial, presided and Father Thomas O'Meara, O.P, preached. Funeral arrangements were handled by Smith- Corcoran Funeral Home. He was buried in the Dominican Section at All Saints Cemetery in Des Plaines, Illinois.