No they are not.
Continental Baptist Churches was created in 1983.
Brotherhood of Baptist Churches was created in 1981.
Association of Reformed Baptist Churches of America was created in 1997.
1st Baptist churches are not a separate denomination they are the first Baptist church that was established in a certain town or city. Most 1st Baptist churches are southern Baptist (although outside of the south this is not always true). As Southern Baptist churches most 1st Baptist church believe in the basic tenants of the Southern Baptist Convention as laid out in the Baptist Faith and Message.
Convention of Philippine Baptist Churches was created in 1935.
Union of Baptist Churches in Serbia was created in 1992.
Association of Regular Baptist Churches was created in 1957.
Association of Baptist Churches in Ireland was created in 1862.
Wisconsin Fellowship of Baptist Churches was created in 1950.
Union of Baptist Churches in the Netherlands was created in 1881.
National Union of Baptist Churches was created in 1981.
Association of Baptist Churches of Chad was created in 1963.