Locating in Montgomery, he entered on a successful practice of his profession, and for a long period of years preserved the reputation of being one of the leading members of the Montgomery bar. In 1855 he was again summoned from private life to represent his party, the Whig, in a contest for congress against Col. James F. Dowdell. Mr. Watts was defeated after an exciting canvass, but the campaign resulted in his acknowledged leadership of his party in the state. In the memorable presidential campaign of 1860, Mr. Watts was the leader of the electoral ticket in Alabama for Bell and Everett. Being a union man and opposed to secession, his patriotism rose superior to his party fealty, and after the election of Mr. Lincoln, Mr. Watts was as pronounced a secessionist as any. Under existing conditions he recognized the fact that not to go with his state was treachery, his position and sentiments being precisely those of Gen. Robert E. Lee. Men of this school of thought deplored the necessity of war and would gladly have averted it if possible, but when it became inevitable there was but one course left open. Consequently in the constitutional convention of 1861 Mr. Watts was as ardent in the expression of southern rights as was Mr. Yancey himself. The country was in the ferment of agitation and hostility. The south was threatened with invasion, and every patriot was stirred. Thomas H. Watts was among the first to raise a regiment and offer his services to the Confederacy. Becoming the colonel of the Seventeenth Alabama regiment, his command saw its first service at Pensacola, which at that time seemed to be destined one of the strategic positions of the approaching conflict, but the regiment was soon ordered to join the army of Gen. Albert Sidney Johnson, in Tennessee. In the battle of Shiloh Colonel Watts displayed the qualities of a soldier equal to those shown by him in other spheres which he had occupied. He was cool, courageous, and daring under fire, to so marked a degree that he won the attention of his superior officers, and his conduct in that battle became a subject of popular comment throughout the country. Much to his surprise, while in camp at Corinth, Miss., he was summoned to Richmond by President Davis, who offered him the portfolio of the attorney general in his cabinet, a place made vacant by the appointment of Hon. Judah P. Benjamin as secretary of war. Responding to the call, Colonel Watts resigned the command of his regiment and went immediately to the seat of the Confederate government. Here he remained in the cabinet of Mr. Davis till October, 1863, when he resigned to offer for the governorship of Alabama.