U.S. Presidents: Madison, Nixon, and Clinton: Crack the easy-level codes and explore their lives

U.S. Presidents: Bush and Obama: Crack the difficult-level codes and explore their lives

U.S. Presidents: Washington, Lincoln, and Grant: Crack the medium-level codes and explore their lives

U.S. Presidents: Adams and Wilson: Crack the difficult-level codes and explore their lives

U.S. Presidents: Kennedy and Bush: Crack the medium-level codes and explore their lives