In July 1922 the anti-Treaty IRA began a concerted campaign of bridge destruction in Co. Wexford, which continued sporadically until March 1923. Its main aim was to impede the Free State army's ability to move around the county, and to make the area generally ungovernable.
Wexford’s Civil War: The Destruction of the Bridges
The Archaeology of Conflict: Wexford in the Civil War, 1922-1923 