This Horace Greeley (1811-1872) daguerreotype was made around 1851. It is currently maintained at the National Portrait Gallery, Smithsonian Institution. The information provided there says:
In 1869, Harper's Weekly called Horace Greeley "the most perfect Yankee the country has ever produced."
Editor, politician, and founder of the New York Tribune, Greeley began his career as a Whig and in 1856 helped establish the new Republican Party.
In the 1840s, he urged a generation to "Go West, young man." Under Greeley's leadership, the Tribune became the first national newspaper, circulating by rail and steamboat lines, to unite the country around his moderate, antislavery position.
Online image, courtesy U.S. National Archives.
The above information is provided by U.S. Portrait Gallery at the Smithsonian Institution.