Texans. Twiggs immediately resigned from the U.S. Army and was made a Confederate general. Lee went back to Washington and was appointed Colonel of the First Regiment of Cavalry in March 1861. Lee's colonelcy was signed by the new president, Abraham Lincoln. Three weeks after his promotion, Colonel Lee was offered a senior command (with the rank of Major General) in the expanding Army to fight the Southern States that had left the Union. Fort Mason, Texas, was Lee's last command with the United States Army. Civil War Resignation from United States Army Unlike many Southerners who expected a glorious war, Lee correctly predicted it as protracted and devastating. He privately opposed the new Confederate States of America in letters in early 1861, denouncing secession as "nothing but revolution" and an unconstitutional betrayal of the efforts of the Founding Fathers. Writing to George Washington Custis in January, Lee stated: Despite opposing secession, Lee said in January that "we can with a clear conscience separate" if all peaceful means failed. He agreed with secessionists in most areas, rejecting the Northern abolitionists' criticisms and their prevention of the expansion of slavery to the new western territories, and fear of the North's larger population. Lee supported the Crittenden Compromise, which would have constitutionally protected slavery. Lee's objection to secession was ultimately outweighed by a sense of personal honor, reservations about the legitimacy of a strife-ridden "Union that can only be maintained by swords and bayonets", and his duty to defend his native Virginia if attacked. He was asked while leaving Texas by a lieutenant if he intended to fight for the Confederacy or the Union, to which Lee replied, "I shall never bear arms against the Union, but it may be necessary for me to carry a musket in the defense of my native state, Virginia, in which case I shall not prove recreant to my duty". Although Virginia had the most slaves of any state, it was more similar to Maryland, which stayed in the Union, than to the Deep South; a convention voted against secession in early 1861. Scott, commanding general of the Union Army and Lee's mentor, told Lincoln he wanted him for a top command, telling Secretary of War Simon Cameron that he had "entire confidence" in Lee. Lee accepted a promotion to colonel of the 1st Cavalry Regiment on March 28, again swearing an oath to the United