A Partial List of When The States Were Admitted to the Union

• 1858: Minnesota
• 1859: Oregon
• 1861: Kansas
• 1863: West Virginia
• 1864: Nevada
• 1867: Nebraska
• 1876: Colorado
• 1889: North Dakota, South Dakota, Montana, Washington
• 1890: Idaho, Wyoming
• 1896: Utah
• 1907: Oklahoma
• 1912: New Mexico, Arizona
• 1959: Alaska, Hawaii

Also, in 1963 DC residents won the right to vote for President and Vice-President of the United States with the ratification of the 23rd Amendment to the Constitution. Good hints for deciphering the election year maps, eh?