Who were the first 20 presidents in alphabetical order?

First 20 presidents in alphabetical order:

Adams, John (1797-1801)

Adams, John Quincy (1825-1829)

Arthur, Chester Alan (1881-1885)

Buchanan, James (1857-1861)

Bush, George (1989-1993)

Bush George W. (2001-2009)

Carter, Jimmy (1977-1981)

Cleveland, Grover (1885-1889, 1893-1897)

Clinton, Bill (1993-2001)

Coolidge, Calvin (1923-1929)

Eisenhower, Dwight D. (1953-1961)

Fillmore, Millard (1850-1853)

Ford, Gerald R. (1974-1977)

Garfield, James A. (1881)

Grant, Ulysses S. (1869-1877)

Harding, Warren G. (1921-1923)

Harrison, Benjamin (1889-1893)

Harrison, William Henry (1841)

Hayes, Rutherford Birchard (1877-1881)

Hoover, Herbert (1929-1933)

Jackson, Andrew (1829-1837)

Jefferson, Thomas (1801-1809)

Johnson, Andrew (1865-1869)

Johnson, Lyndon B. (1963-1969)

Kennedy, John F. (1961-1963)

Lincoln, Abraham (1861-1865)

Madison, James (1809-1817)

McKinley, William (1897-1901)

Monroe, James (1817-1825)

Nixon, Richard M. (1969-1974)

Obama, Barack (2009-2017)

Pierce, Franklin (1853-1857)

Polk, James K. (1845-1849)

Reagan, Ronald (1981-1989)

Roosevelt, Franklin D. (1933-1945)

Roosevelt, Theodore (1901-1909)

Taft, William H. (1909-1913)

Taylor, Zachary (1849-1850)

Truman, Harry S. (1945-1953)

Trump, Donald J. (2017-)

Tyler, John (1841-1845)

Van Buren, Martin (1837-1841)

Washington, George (1789-1797)

Wilson, Woodrow (1913-1921)