The U.S. postage rate for domestic First Class mail increased from 41 cents to 42 cents on May 12, 2008. That rate covers standard-size letters that weigh up to 1 ounce. The charge for additional ounces remained at 17 cents.
The rate increased again to 44 cents on May 11, 2009, where it remained until Jan. 22, 2012, when it increased to 45 cents. The rate for additional ounces, however, increased to 20 cents on April 17, 2011. As of Jan. 26, 2014, the rates for first class postage had risen to 49 cents for the first ounce and 21 cents for each additional ounce. During the same time, the cost to mail a postcard increased from 24 cents to 34 cents.