From the Virginia Tech Department of History web site:

Letters from a correspondent of the Missouri Republican

[Written before the battle]
CAMP SAN JUAN DE BUENA VISTA.
Five miles south of Saltillo, Mexico Jan. 20.
Mexican Campaigning.

"...the hardships of the day were aggravated by another circumstance. It took so much time to cross over the artillery and staff wagons, (who were given preference over the volunteers,) that more than half the company wagons of the regiment of volunteers had to be left on the opposite side of the river from the troops. The consequence was, that after tugging all day at the ropes, pulling wagons over, and going without any dinner, the majority of the men had to lie down at night in their wet clothes without tents, blankets or food.

Many were the accidents and narrow escapes of the day. Several men were washed away from the wagons, and were only saved by extraordinary exertions. One of the artillerists was washed off the gun carriage, and both wheels passed over his legs, yet they were not broken, as the swiftness of the current doubtless prevented the whole weight of the cannon from coming upon him. Several mules were drowned. A quartermaster's wagon was upset in the Sabinas, and his papers and stores floated down the in admirable confusion.

Neither was there any want of commanders; for both the generals, with all the colonels, the whole staff, and all the wagon masters, were giving orders at the top of their lungs, and with the most violent gesticulations.

In the midst of this babel of orders and counter orders, mingled as it was with the roaring of the mountain torrent, the shouting of officers, and the imprecations of the wagoners, Maj. Warren quietly slipped off to one side amongst the bushes to take the matter more easily. Under some brush by the side of the river, he discovered an Arkansas volunteer sitting down, from whose clothes the water was still dripping. His head was between his knees, and he was deeply soliloquizing.

"Well," said he, "if this is war, I ain't in no more."

"What is the matter?" inquired the major.

"Why," answered the Rackensacker, "I was standing on the bank up there with my hands in my pockets, thinking I might as well take it easy, as I didn't own any of them wagons, when along comes the general, and shouted out, 'what are you doing there on the bank, you lazy fellow? Why don't you jump in and help that wagoner?' without taking time to take a chaw of tobacco, I pitched in like a frog and seized hold of the wagon and worked as hard as if I had been at a gander pulling. And was still at it, a giving of orders equal to the best of them, when here comes a general's aidercong and screaming out 'What the d--l are you doing in the way?' With that I leaped out of the river like a water dog. Now you see stranger, I came here to fight them Mexicans, and not to make a mule of myself to haul wagons, and I say again, if this is war I ain't in no more." [ANP]