It's because you didn't go far enough north. Need to be further up towards fredrick. In DC and just below the beltway is excellent large mouth fishing. I was suppose to be up there a few weeks ago before I banged myself up. Still think I will bring my bass boat and fish some of the creeks above the brackesh water.

If you are in deeper water (20 feet and down) then take a gulp alive worm and drop shot that to just off the bottom with a sinker. In shallower water try texas rigged senko worms or rapalas. Worked great for us over the past few years