[4] In 1879, Farwell and his brother John were part of a group of Illinois businessmen and politicians responsible for construction of the Texas State Capitol building.

The Farwell's reward for this was to become owners of over 3 million acres of land in Texas, upon which they founded the XIT Ranch.

Together, they were the parents of nine children, only four of whom lived to adulthood:[9] After a long illness,[22] Farwell died in Lake Forest, Illinois on September 23, 1903.

[23] Upon her death in 1918, his other daughter Grace inherited the mansion, and when it burned in 1920, the McGanns hired New York architects Delano and Aldrich to rebuild it in a Federal style with neo-Palladian brick and was finished in 1923 with original landscape was designed by Frederick Law Olmsted.

[24] Through his daughter Anna, he was a grandfather of Ethel Leroy De Koven (1885–1943), who married broker Hans Kierstede Hudson.

Anna later married the composer Reginald de Koven, and became a successful socialite, novelist and amateur historian.