The political campaign of 1866 was one of greater excitement than had ever been witnessed in this country, except in the election of a President. The chief interest was in choosing members of the House of Representatives for the Fortieth Congress, and in controlling the Legislatures which were to choose senators of the United States and pass upon the Fourteenth Amendment. In elections of this character, even in periods of deepest interest, the demonstrations of popular feeling are confined to the respective States, but in this instance there were no less than four National Convention, three of them, at least, of imposing magnitude and exerting great influence on popular action. The first was called by the friends of President Johnson to meet in Philadelphia on the 14th of August. The object was to effect a complete consolidation of the Administration Republicans and the Democratic party, under the claim that they were the true conservators of the Union, and that the mass of the Republican party, in opposing President Johnson, were endangering the stability of the Government. A large majority of the delegates composing the convention were well-known Democrats, and they were re-enforced by some prominent Republicans, who had left their party and followed the personal fortunes of President Johnson. The most conspicuous of these were Montgomery Blair (who for some years had been acting with the Republicans), Thurlow Weed, Marshall O. Roberts, Henry J. Raymond, John A. Dix and Robert S. Hale in New York, Edgar Cowan of Pennsylvania, James R. Doolittle and Alexander W. Randall of Wisconsin, O. H. Browning of Illinois, and James Dixon of Connecticut. The Democrats were not only overwhelmingly in the majority, but they had a very large representation of the leaders of the party in several States. So considerable a proportion of the whole number were men who had been noticeably active as opponents of Mr. Lincoln's Administration, that the convention was popularly described as a gathering of malignant copperheads, who, during the war, could not have assembled in the city where they were now hospitably received, without creating a riot. Among the most conspicuous and most offensive of this latter class,--those who had especially distinguished themselves for the bitterness, and in some cases for the vulgarity, of their personal assaults upon Mr. Lincoln,--were Mr. Vallandingham of Ohio, Fernando Wood, Benjamin Wood and James Brooks of New York, Edmund Burke and John G. Sinclair of New Hampshire, Edward J. Phelps of Vermont, George W. Woodward, Francis W. Hughes and James Campbell of Pennsylvania, and R. B. Carmichael of Maryland. Among the leading Democrats, less noted for virulent utterances against the President, were Samuel J. Tilden, Dean Richmond and Sanford E. Church of New York, John P. Stockton and Joel Parker of New Jersey, David R. Porter, William Bigler and Asa Packer of Pennsylvania, James E. English of Connecticut, Robert C.