His political principles, opinions, judgments, were framed upon those of the men of the times of Washington.  From these, to the last, he never swerved.  The copy was well executed.  His conversation on subjects of state was as instructive and interesting as upon professional topics.  He had the same reach of thought, and exhibited the same comprehensive mind, and sagacity quick and far seeing, with regard to political things and men, as he did in professional affairs.  His influence was, therefore, hardly the less from the fact that he was not actively engaged in political life.  There was an additional weight given to his judgment, arising from his being a disinterested beholder only.  The looker-on can sometimes form a more independent and impartial opinion of the course and results of the contest, than those who are actually engaged in it.

But at length, in June, 1813, he was persuaded to accept the post of a Senator of the United States, and took his seat that month.  He was in Congress during the sessions of 1813 and 1814.  Those were very exciting times; party spirit ran very high, and each party put forward its most prominent and gifted men.  Both houses were filled by the greatest intellects of the country.  Mr. Mason found himself by the side of Rufus King, Giles, Goldsborough, Gore, Barbour, Daggett, Hunter, and other distinguished public men.  Among men of whatever party, and however much some of them differed from him in opinion or political principle, there was not one of them all but felt pleasure if he spoke, and respected his uncommon ability and probity, and his fair and upright demeanor in his place and station.  He took at once his appropriate position.  Of his associates and admirers in the other house, there are some eminent persons now living who were occasional listeners to his speeches and much struck with his ability; together with Pickering, Benson, Pitkin, Stockton, Lowndes, Gaston, and Hopkinson, now all deceased, who used to flock to hear him, and always derived deep gratification and instruction from his talents, character, and power.

He resigned his seat in the Senate in 1817.  His published speeches are not numerous.  The reports of that day were far less complete than now, and comparatively few debates were preserved and revised.  It was a remarkable truth, that he always thought far too lightly of himself and all his productions.  I know that he was with difficulty persuaded to prepare his speeches in Congress for publication; and in this memorial of himself which I have before me he says, with every appearance and feeling of sincerity, that he “has never acted any important part in life, but has felt a deep interest in the conduct of others.”

His two main speeches were, first, one of great vigor, in the Senate, in February, 1814, on the Embargo, just before that policy was abandoned.  The other was later, in December, 1815, shortly before the peace, on Mr. Giles’s Conscription Bill, in which he discussed the subject of the enlistment of minors; and the clause authorizing such enlistment was struck out upon his motion.