The Baptist Convention of the Maritime Provinces was founded in 1846. The Convention of Atlantic Baptist Churches was formed in 1905-1906 as the United Baptist Convention of the Maritimes by a union of Free, or Free Will, Baptists and Regular Baptists. With the addition of Newfoundland to Canada in 1949, the name was changed to the United Baptist Convention of the Atlantic Provinces. Many of these churches still carry United Baptist in their official name. The Convention joined with two other conventions in 1944 to form the Canadian Baptist Federation. The largest regional union in Canada, in 2003 the CABC consists of over 62,000 members in 538 churches and 21 associations across the Atlantic provinces (New Brunswick, Newfoundland, Nova Scotia & Prince Edward Island). The CABC in subdivided for local association cooperation into five regions. According to Article I of the Constitution of the Convention of Atlantic Baptist Churches, it is "composed of those bodies which have agreed to work together upon the basis of the historic Baptist position that the Bible is the all-sufficient ground of faith and practice".
The offices of the CABC are located in Saint John, New Brunswick.