James J. Hill (1838-1916) became one of the leading railroad barons in America in the closing decades of the 19th century and first decade of the 20th. Allied with banking magnate J.P. Morgan, Hill worked to control a vast railroad network stretching from Chicago to the Pacific Northwest and including three railroads: the Great Northern, Northern Pacific, and Burlington. Born in Canada, Hill moved to St. Paul before the Civil War and by 1879 was part owner of a local railroad company. By the turn of the century, he was a multi-millionaire and one of the nation's most important entrepreneurs. He lived most of his life in St. Paul and built a large and prestigious mansion, designed by the architectural firm Peabody and Steams, on Summit Avenue in 1890.

Robert Peabody was born in New Bedford, MA, on February 22, 1845. He received an A.B. degree in architecture from Harvard University in 1866 and a master's degree in 1870. In 1868, he graduated from the École des Beaux Arts in Paris. He began practicing architecture in Boston in 1870 and was awarded the FAIA in 1889. Peabody died on September 23, 1917, in Marblehead, MA.

John Steams graduated from Harvard College in 1863 and was named an FAIA in 1894. He died in Duxbury, MA, on September 17, 1917.