 Of these three regiments, the 41st was the smallest, having been reduced to 371 active duty men through sickness and incapacitation during their months of training and marching.Above Hazen in the chain of command was Brigadier General William "Bull" Nelson, in charge of the 4th Division, in the vanguard of the advance toward the action at Pittsburg Landing.For most of April 6, the division was stopped eight miles away from the river crossing to Pittsburg Landing, waiting for promised local guides who could help them find their way through the swampy ground in front of them.