As a member of the House of Representatives Mr. Davis rapidly and steadily won upon the good opinion of his associates, and the favorable estimate of him, entertained by his constituents and friends, was confirmed by his greatly advanced reputation at the period of his withdrawal from Congress in the ensuing summer. He became prominent, less by the frequency with which he claimed the attention of the House, than by the accuracy of his information, the substantial value of his suggestions and the easy dignity of his demeanor. His speeches, though not comparable with his senatorial efforts, were characterized by great perspicuity, argumentative force, and propriety of taste, and frequently rose to the dignity of true eloquence. They, in every instance, gave promise of that rhetorical finish, power of statement, unity of thought and logical coherence, which, in subsequent years, were so appropriately illustrated on other theaters of intellectual effort. Mr. Davis participated prominently in the debates upon the Oregon excitement, Native Americanism, and the various other contemporary topics of interest, which were then before Congress, but was especially prominent in the discussion of military affairs, the interests and requirements of the army, and the measures devised for the prosecution of the Mexican war. Upon the latter subjects his experience was of great practical value. On the 19th of December, 1845, he offered the following resolutions: "_Resolved_, That the Committee on Military Affairs be instructed to inquire into the expediency of converting a portion of the forts of the United States into schools for military instruction, on the basis of substituting their present garrisons of enlisted men, by detachments furnished from each State of our Union, in the ratio of their several representation in the Congress of the United States." "_Resolved_, That the Committee on the Post-office and Post-roads be required to inquire into the expediency of establishing a direct daily mail route from Montgomery, Alabama, to Jackson, Mississippi." The occasion of these motions was the first upon which he occupied the floor of the House. On the 29th of December, Mr. Davis spoke in a very earnest and impressive manner upon Native Americanism, which he strongly opposed, and on subsequent occasions addressed the House in favor of the bill to receive arms, barracks, fortifications, and other public property, the cession of which to the Federal Government, by Texas, had been provided to take place upon its admission to the Union; in favor of the proposition to raise additional regiments of riflemen; in opposition to appropriations for improvement of rivers and harbors; upon the Oregon question, and in favor of a resolution of thanks to General Taylor and his army.