[1] Chearnley joined the British Army's 8th (The King's) Regiment of Foot under Sir Henry Bayly as an ensign on 26 November 1825 and attained the rank of lieutenant on 15 October 1829.

[3] William Chearney was made a captain of the 8th (The King's) Regiment of Foot stationed in Halifax, Nova Scotia on 7 August 1835.

[6] Chearnley, an avid hunter and sportsman, explored and took advantage of the wilderness in Nova Scotia and New Brunswick during the early 1850s.

[1] Chearnley also traveled to Newfoundland, where he hunted caribou alongside his brother John and a Mi'kmaw guide, James Cope.

[8] At Saint Augustine's Roman Catholic Cemetery in Chester, Nova Scotia, Chearnley erected a stone with the following inscription: "In memory of Joseph Pennall, Indian, By Wm.

On 4 March of that year, Chearnley corresponded with Joseph Howe, Nova Scotia's first Commissioner of Indian Affairs.

Chearnley was in command of the volunteer rifle brigade on 24 July 1860 upon the landing of the Prince of Wales (future King Edward VII) in Halifax.

"[16] Col. William Chearnley accepted the colours on behalf of the 63rd Regiment on 10 November 1862, a gift from the City of Halifax in recognition of their dedication to training for Canada's defense.

Chearnley, joined by Campbell Hardy, and Westcote W. Lyttleton, held an exhibition in the armoury of the volunteers' drill-room in Halifax.

[19][20] Chearnley, A. Downs, and C. Hardy in 1864 outlined regulations for the Nova Scotia Inland Fisheries and Game Protection Society.

[14] In October 1868, the Provincial Agricultural and Industrial Exhibition of Nova Scotia was held in Halifax, and he was a member of its general committee.

[23] The battalion turned out in force in July to honor Col. Chearnley’s funeral, where the 63rd Regiment conducted the firing salute as part of the tribute.