The family lived in Newtown, where between 1902 and 1911 Croskery ran his own drapery and tailoring business in Riddiford Street, then about 1917 moved to Lyall Bay.

[2] Croskery helped to found the Wellington Retail Soft-goods Employees' Union in February, 1912, and served as its secretary.

In 1946, Croskery was elected President of the Federation of Labour, succeeding Angus McLagan; he held office until his death in 1952.

He served as FOL President during a time of difficulty for the labour movement, including the formation of the rival New Zealand Trade Union Congress in 1950, the bitter 1951 waterfront dispute, and political opposition from a resurgent National Party.

He worked well with FOL Vice-president Fintan Patrick Walsh, and was an exemplary representative for the New Zealand labour movement overseas, serving as a delegate to the World Trade Union Conferences in London in 1945 and in Paris in 1949, as well as to the International Labour Organization's conference in Geneva in 1949.

[2] A dapper, well-dressed man who was always smoking a pipe, Croskery suffered from chronic bronchitis and emphysema in later years.