Fort Donelson was defended with twenty-eight regiments of infantry, two independent battalions, one regiment of cavalry, artillerymen for six light batteries, and seventeen heavy guns. This added up to approximately 18,000 defenders. The Federal army, under the leadership of General Ulysses S. Grant, managed to create an attacking force that numbered approximately 20,000 soldiers. Along the line fierce fighting without much success for Federal troops was still occurring upon the arrival of the 2nd Iowa. During the fighting the previous day, a brigade advanced on the extreme left, where the 2nd Iowa was eventually placed, and suffered severe losses before retreating back to the skirmish line. After their arrival on February 14, 1862, the 2nd Iowa was placed at the extreme left of Grant's force as a part of General Charles Smith's division, and Colonel Tuttle sent companies A and B ahead as skirmishers. The rest of the regiment spent a night on the line without tents or blankets to protect them from the brutal winter weather.