Yet he never made it an issue, even in his Cabinet, where, as he well knew, very serious doubts existed as to the expediency of the measure. He was deeply pained by the unjust attacks and groundless criticism of which he was the subject, but he accepted the adverse judgment of the Senate as a constitutional binding decision of the question, and of that decision he never complained. In a message to the Senate of the 31st of May, 1870, he urged the annexation of Santo Domingo. He said, "I feel an unusual anxiety for the ratification of this treaty, because I believe it will redound greatly to the glory of the two countries interested, to civilization, and to the extirpation of the institution of slavery." He claimed for the scheme great commercial advantages, that it was in harmony with the Monroe doctrine, and that the consummation of the measure would be notice to the states of Europe that no acquisitions of territory on this continent would be permitted. In his second inaugural address General Grant referred to the subject in these words: "In the first year of the past administration the proposition came up for the admission of Santo Domingo as a Territory of the Union. . . . I believe now, as I did then, that it was for the best interests of this country, for the people of Santo Domingo, and all concerned, that the proposition should be received favorably. It was, however, rejected constitutionally, and therefore the subject was never brought up again by me." General Grant considered the failure of the treaty as a national misfortune, but he never criticised the action of its opponents. General Grant's firmness was shown in his veto of the Senate currency bill of 1874. It is known that unusual effort was made to convince him that the measure was wise in a financial view, and highly expedient upon political grounds. The President wrote a message in explanation of his act of approval, but upon its completion he was so much dissatisfied with his own argument that he resolved to veto the bill. Hence the veto message of April 22, 1874.