The accomplishment of Sabine Pass was not to break the blockade of Galveston (which, by the way, remained a haven for blockade runners to the end of the war). It was to thwart the attempt of The Lincoln to seize east Texas' cotton stores, the so-called "breadbasket of the confederacy" during the war. The dissolution of foreign trade and the war had left the north short on cotton and in economic chaos in those industries. That cotton was in east Texas, unimpeded by the war, and The Lincoln set out to get it. His mission was of two purposes - get the cotton for the north, and in doing so take from the south what it had been running through the blockades for its own sustanence.
Sabine Pass thwarted this mission, forcing The Lincoln to try again. The next try was called the Red River campaign. He put together a 45,000 man invasion force along with 58 warships - the largest inland fleet ever assembled on the North American continent. He sent them to invade from northern Louisiana. They were thwarted again at Mansfield.