DISEMBARKED MARINES
Just a thought. Being a Marine, I'm aware that ships companies of Marines were sent along with a landing force as additional infantry or even as cannon crews. Huston had them along in Texas, they played a big role at New Orleans, etc. etc. I do have research material, I just have neglected this period in my historical curiosities.
Maybe like regular line infantry but somewhat less troops. But much much better accuracy, more ammo, mcuh better melee and much much higher morale!