In 2007, the U.S Mint's Presidential Dollar series debuted, which honors our nation's presidents in the order they served as heads-of-state. The third-year 2010 proof set portrays Presidents Millard Fillmore, Franklin Pierce, James Buchanan and Abraham Lincoln. The 2011 set features tributes to Andrew Johnson, Ulysses Grant, Rutherford Hayes and James Garfield. Edge-incused lettering displays the year of issuance, "E Pluribus Unum," "In God We Trust" and the mintmark. A Statue of Liberty engraving adorns the reverse. Each proof features frosted engravings and mirror backgrounds.