A native of Britain, Kennedy was apprenticed in architectural offices in London and Dublin between 1862 and 1872, after which he emigrated to the U.S. In 1880, he entered partnership with Thomas Dixon (the formation of this partnership was announced March 16, 1880 in the Baltimore American and Commercial Advertiser). Kennedy’s letter to the American Architect and Building News claiming credit for designing the McDonogh Institute suggests that this was among the formation of his partnership with Dixon. This partnership was short-lived; the firm of Dixon & Kennedy was listed in the Baltimore City Directory for only one year, 1881, after which Dixon and Kennedy both maintained independent listings. Kennedy established an office at 47 Lexington Street in 1882 (renumbered 12 East Lexington Street in 1887) and remained there until 1895, when he moved to 113 North Charles Street. The 1904 fire apparently displaced him, and he moved to 331 North Charles Street in 1905. He was elected to the Baltimore Chapter of the AIA in 1899. In 1902, he lived in Mt. Washington. At the time of his death, Kennedy resided at 2106 Elsinor Avenue, in the Walbrook section of West Baltimore. He was killed in a collision with an automobile while riding his bicycle.
In addition to an extensive residential practice, Kennedy designed numerous Roman Catholic churches and institutional buildings, including Calvert Hall College (1890), Loyola College (1898), St. Paul’s Church (1902), and Mary Meletia Hall (College Hall) at the College of Notre Dame (1910). His obituary cited his extensive connections in the Roman Catholic community, and his membership in several Catholic organizations including the Knights of Columbus, St. Vincent de Paul Conference, and the Catholic Benevolent Legion.
A collection of Kennedy’s drawings, watercolors, and photographs was donated to the Maryland Historical Society by his daughter, Florence J. Kennedy, in 1925.