As you probably guessed, my guess the speaker question has an unexpected answer. The speaker was Congressman Michael Walsh of New York. His entry in the Biographical Directory of the United States Congress reads as follows:
WALSH, Michael, a Representative from New York; born in Youghal, near Cork, Ireland, May 4, 1810; completed preparatory studies; was graduated from Trinity College, Dublin, Ireland; immigrated to the United States and settled in Baltimore, Md.; learned the trade of lithographic printer; moved to New York City; member of the State assembly in 1839; in 1843 established the Subterranean, which he stopped after two years when convicted for the publication of a libel; elected as a member of the State assembly in 1846 and again in 1848; elected as a Democrat to the Thirty-third Congress (March 4, 1853-March 3, 1855); unsuccessful candidate for reelection in 1854 to the Thirty-fourth Congress; after his term in Congress was employed as a newspaper reporter; died in New York City March 17, 1859; interment in Greenwood Cemetery, Brooklyn, N.Y.
James L. Huston describes Rep. Walsh as having "a distinct class viewpoint on the economics of American life, particularly on the sufferings of the Irish in New York City. He found no reason to celebrate the northern laborer in comparison with the lot of a slave." "Walsh's statements were quite unique in the Kansas-Nebraska debate, but they obtained considerable reprinting in the northern press."