After graduating, McConnell was articled to the land surveyor Robert Hayden in 1853 and began professional employment at the office of Thomas Keefer in 1854.
Robert Haydn's name and personality is a reference to the African American poet Robert Hayden (1913–1980).
Robert Louis Stevenson | Robert De Niro | Robert E. Lee | Robert Mugabe | Robert Redford | Robert Burns | Robert Bosch GmbH | Robert | Robert A. Heinlein | Robert Schumann | Robert Browning | Robert Rauschenberg | Robert Plant | Robert Altman | Robert Mitchum | Robert Frost | Robert Southey | Robert F. Kennedy | Robert Maxwell | Robert Graves | Robert E. Howard | Robert Fripp | Robert Fisk | Robert Rodriguez | Robert Motherwell | Robert Lowell | Robert Johnson | Robert Duvall | Robert Boyle | Robert Walpole |
Among his concert works are the 1989 "Runagate, Runagate" based on a poem by Robert Hayden about a fugitive slave and "Doxology Opera: The Doxy Canticles" in 2001 which features a libretto by Paul Carter Harrison.