 Besides strengthening the Union naval blockade of the Texas coastline, the shelling and capture of Sabine Pass was to deter Confederate ground forces from moving southwestward on the Texas coast to augment Galveston's defense.And, it was to open the way for the Union invasion of Texas, which almost a year later was attempted by a combined force of Union naval and army forces at the Second Battle of Sabine Pass.Sabine Pass is the waterway serving as the outlet of the Sabine Lake estuary formed by the confluence of the Neches and Sabine rivers.