PROFILE of GEORGE B. SWARTHOUT
8th MO Infantry (US) Company H
	8th Missouri Advancing at Fort Donelson

"Meantime the regiments slowly followed the skirmishers.   About quarter the way up they received the first volley from the hill-top around which it ran, a long line of fire disclosing somewhat of the strength of the enemy.   Instantly, under order of Colonel Morgan Smith, both his regiments laid down.   The skirmishers were the chief victims.
 
George B. Swarthout, captain of Company H, Eighth Missouri, was killed, gallantly fighting far in advance.   Soon as the fury of the fire abated, both regiments rose up and rushed on; and in that way they at length closed upon the enemy, falling when the volleys grew hottest, dashing on when they slackened or ceased.

Meanwhile their own fire was constant and deadly.   Meanwhile, also, Colonel Cruft's line was marching up in support and to the right of Colonel Morgan Smith.   The woods through which he was moving seemed actually to crackle with musketry.   Finally, the Eighth Missouri and Eleventh Indiana cleared the hill, driving the rebel regiments at least three-quarters of a mile before them and halting within 150 yards of the intrenchments behind which the enemy took refuge.   This was about 5 o'clock, and concluded the day's fighting.
 
In my opinion it also brought forth the surrender."

You can read Brig. Gen. Lewis Wallace's entire report at Civil War Home.
(And, yes, he was the Lew Wallace who wrote "Ben Hur".)