paragraph: Since the beginning of the American Civil War, Hamilton has been depicted on more denominations of US currency than anyone else. He has appeared on the $2, $5, $10, $20, $50, and $1,000. His likeness also began to appear on US postage in 1870. His portrait has continued to appear on US postage and currency, and most notably appears on the modern $10 bill, though it was announced on 18 June 2015 that his portrait would be replaced by that of a woman, to reflect the changing nature of American democracy and society. Hamilton also appears on the $500 Series EE Savings Bond. The source of the face on the $10 bill is John Trumbull's 1805 portrait of Hamilton, in the portrait collection of New York City Hall. The first postage stamp to honor Hamilton was issued by the U.S. Post Office in 1870. The portrayals on the 1870 and 1888 issues are from the same engraved die, which was modeled after a bust of Hamilton by Italian sculptor Giuseppe Ceracchi The Hamilton 1870 issue was the first US Postage stamp to honor a Secretary of the Treasury. The three-cent red commemorative issue, which was released on the 200th anniversary of Hamilton's birth in 1957, includes a rendition of the Federal Hall building, located in New York City. On March 19, 1956, the United States Postal Service issued the $5 Liberty Issue postage stamp honoring Hamilton. 
question: In what year did Hamilton first appear on both currency and postage?
answer: 1870