During the Presidency of James K. Polk...

   27th star added to the flag for Florida, July 4, 1845 
   Naval Academy opened at Annapolis, Maryland, October 10, 1845 
   Texas becomes the 28th state, December 29, 1845 
   Uniform election day established, January 23, 1846 
   War declared against Mexico, May 13, 1846 
   First known baseball game played under rules established by Alexander Cartwright, at Elysian Fields, Hoboken, New Jersey, 
June 19, 1846 
   Treaty concluded with Great Britain establishing the Oregon boundary at the 49th parallel, June 15, 1846 
   Independent Treasury Act approved August 6, 1846 
   Smithsonian Institute created August 6, 1846 
   Elias Howe patents the sewing machine, September 10, 1846 
   Rotary printing press invented 1845-1846 
   Treaty signed with New Grenada (Colombia) granting U.S. right of way across Isthmus of Panama, December 12, 1846 
   Iowa becomes the 29th state, December 28, 1846 
   Postage stamp authorized by Act of Congress, March 3, 1847 
   Congress provided for gas lighting of the Capitol and grounds, March 3, 1847
   An advance party of Mormons entered the valley of the Great Salt Lake, July 22, 1847 
   Gold discovered in California, January 24, 1848 
   Treaty signed with Mexico, February 2, 1848 
   Wisconsin becomes the 30th state, May 29, 1848 
   Cornerstone of the Washington Monument laid, July 4, 1848 
   First Women's Rights Convention held at Seneca Falls, New York, July 19, 1848 
   Territorial government of Oregon established, August 14, 1848 
   Department of the Interior created March 3, 1849 
   Coinage of the gold dollar and double eagle ($20), March 3, 1849 
   In the "Fabulous Forties" Emerson, Thoreau, Hawthorne, Longfellow, Whittier, Lowell, Poe, and Cooper produced the "Golden Age of American Letters."