The regiment was called out on service on 26 August 1939 and then details were placed on active service on 1 September 1939, under the designation 'The Lincoln and Welland Regiment, CASF (Details)', for local protection duties. The details were formed as an active service battalion and designated 'The Lincoln and Welland Regiment, CASF' on 15 August 1940. It was redesignated the '1st Battalion, The Lincoln and Welland Regiment, CASF' on 7 November 1940. The unit served in British Columbia, as part of the 13th Infantry Brigade, and in Newfoundland in a home defence role as part of Atlantic Command. On 16 July 1943 it embarked for Britain. On 25 July 1944, the battalion landed in France as a part of the 10th Infantry Brigade, 4th Canadian Armoured Division, and it continued to fight in North West Europe until the end of the war. The overseas battalion was disbanded on 15 February 1946. Source: Canada.ca