An undated portrait of U.S. president Millard Fillmore, the 13th president from 1850 to 1853, succeeding Zachary Taylor. (AP Photo)
Exploring the most important 55 months in American history
An undated portrait of U.S. president Millard Fillmore, the 13th president from 1850 to 1853, succeeding Zachary Taylor. (AP Photo)