His son Joseph Kirby (1844–1937) enlisted as mercenary in the 184th Regiment of New York State Infantry of the Union Army during the American Civil War and returned to Canada in 1865 and joined the Ashberminam Company of Volunteers during the Fenian Raids of 1866.

In 1911 William Kirby set up as a merchant in Lochairn, later named at his instigation Rocky Mountain House after the Hudson's Bay Fort built nearby on the North Saskatchewan River in 1799.

In 1943 he fought as a troop commander with the 24th and 25th Field Regiments and was part of the force that stormed the island of Kiska in the Aleutians in August, 1943, only to find that the Japanese had slipped away two weeks earlier.

The Social Credit government of Ernest Manning was re-elected with an increased majority and, even though the size of the legislature had expanded, the Tories were reduced to a single seat despite more than doubling their share of the popular vote.

[1] In 1967, Justice Kirby was named by Premier Manning to conduct a one-man inquiry into allegations of influence peddling by Social Credit cabinet minister Alfred Hooke and former treasurer Edgar Hinman.