It was believed that the war was over; but, in freely expressing willingness to give up the command I had long exercised, to which I had no claim based upon rank, I did not hesitate to say that: "If the war should be continued, and an additional company of engineer soldiers was authorized to be raised, thus creating an engineer battalion, I would be more than willing to command it in the field: provided, I was made Major, by brevet, and assigned to duty with that rank".
In my official report for the month of March, 1848, it is stated: "During the month, daily instruction [of the company] in branches pertaining to engineering has been omitted, I have thought it best to pay more attention to their improvement in writing and arithmetic. The infantry exercises are continued".
On the 1st of May, I reported: "During the month of April the course of instruction and drill pursued in March has been continued, with satisfactory results".
"Three privates of this company have been appointed [by the government at Washington] commissioned officers. Three sergeants, all men of intelligence, education and character, have been recommended [by me], in compliance with law, for commissions; they having all been repeatedly distinguished for gallant and high soldierly conduct in battle. [As yet] none of these sergeants have received [appointments]".
When it became generally known in the army that the Mexican Government had agreed to the proposed treaty of peace, and that the formal ratification would soon be consummated, I requested the senior engineer, Captain R. E. Lee, to direct me to sell the tools, etc., of the engineer train, in the city of Mexico: order me to proceed to the coast by the first opportunity, for the purpose of looking up, and accounting for, a large amount of engineer property for which the estate of the late Captain A. J. Swift was responsible; and authorize me to turn over the command of the engineer company to Lieutenant McClellan, when I started for the coast.
In compliance with Captain Lee's instructions, the tools were sold. They brought more than they had originally cost in the United States. I left the city of Mexico the day the treaty of peace was signed on the part of the Mexicans; and accompanied General Persifor F. Smith to Vera Cruz, at which place he was charged with making all preparations for the transportation of the army to the United States. Before leaving the City of Mexico I turned over the command of the engineer company to Lieutenant McClellan. I was detained in Vera Cruz about two weeks, obtaining information in regard to, and making disposition of, the public property in that vicinity, for which Captain Swift's estate was then held responsible.
The accounting officers of the government in Washington, had charged against him, on their books, the value of large amounts of property which had been shipped to, but never received by him. Several vessels, partly loaded with portions of that property, were shipwrecked by northers during the siege of Vera Cruz. In the time I spent at that place after the war ended, I obtained knowledge which enabled me to clear up all accounts against the estate of Captain Swift. The amount of that nominal indebtedness far exceeded the value of his property; which would have been unfairly sacrificed to the government, and have left his name unjustly tarnished as that of a defaulter, if conclusive evidence of the facts in the case had not been furnished to the accounting officers.
The engineer company, under Lieutenant McClellan, accompanied by all the engineer officers from the City of Mexico, left that city on the 28th of May, 1848, and marched to Vera Cruz. From the latter place the company was transported by steamer to New York City; arrived at West Point, N. Y., on the 22nd of June; reported to the superintendent of the Military Academy, and was immediately ordered to report to Captain George W. Cullum, of the engineer corps, as its new commander. I remained about a week in Vera Cruz after the company sailed; arrived at West Point in July; and was ordered to report to Captain Cullum.
A short time thereafter, I asked to be relieved from duty with the company; and applied for six months leave of absence. The leave was granted, and it was understood that, on its expiration, I would be ordered to other engineer service.
Before the expiration of my leave, the war men of the company procured the passage of an act by Congress, authorizing their discharge from the service. Under that act nearly all the men of the company, who had served in Mexico, immediately obtained their discharge from the army. This virtually reduced the company to the detachment of recruits which had been collected and retained at West Point.