These extracts prepare the way for the next scene in the drama. UNION OF ALL PARTIES NECESSARY AGAINST THE SLAVE POWER. LETTER TO A MASSACHUSETTS COMMITTEE, MAY 29, 1854. SENATE CHAMBER, May 29, 1854. Gentlemen,--For the present my post of duty is here, so that I must forego the pleasure of meeting our friends on Wednesday next. The Massachusetts host, I am glad to learn, will be reinforced on that occasion by brave voices from other States. Mr. Giddings you will be glad to welcome. Could I meet my fellow-citizens, I should not lose the opportunity of sounding the alarm and exhorting them to action. The Nebraska Bill has passed, but it is a mistake to suppose that the propagandists of Slavery will stop here. Other audacities are at hand. More land from Mexico is sought, on which to extend a nefarious institution. The calamities of war with Spain, incalculably disastrous to the commerce of New York and Boston, are all to be braved in order to appropriate slaveholding Cuba. An intrigue is now pending to secure a foothold in Hayti; and even the distant valley of the Amazon is embraced in these gigantic schemes, by which the despotism of the Slave Power is to be established, while you and I, and all of us from the North, are to bow down before it. For myself, I will not bow down; but, Gentlemen, you will understand that no individual can effectually oppose these schemes. This can be done only in one way. As all at the South, without distinction of party, unite for Slavery, so all at the North, without distinction of party, forgetting vain differences of Whig and Democrat, must unite for Freedom, and, rising in majority and might, take control of the National Government. For this work the people are now ready; and they can surely accomplish it, if they will. The only impediment, at this moment, is to be found in those blind or selfish politicians who perversely seek a triumph of mere party, instead of a triumph of Freedom. Neither the Whig party nor the Democratic party, through its national organization dependent on slaveholding wings, is competent to the exigency. The slaveholding wings can be kept in concert with the Northern wings only when they give the law to the movement. For a poor triumph of party, the North yields, in advance, all that is dear to it, and, while vainly calling itself _national_, helps to instal the _sectional_ power of Slavery in the National Government. This must be changed.