English: The Dawson Cover is the rarest and most important cover in Hawaiian postal history. The envelope is the only known cover bearing the Hawaiian 2c value "Missionary" stamp. It is the only cover with two different denominations from the "Missionary" stamp series.

1852 Hawaiian Missionaries and U.S. Stamps mixed franking cover with 1851 5¢ and 2¢ stamps together with 2 United States 3¢ Brownish Carmine stamps tied by "San Francisco Cal. 27 Oct." circular datestamp. On this cover the Missionary stamps prepay the 5c Hawaiian postage and 2c ship captain's fee, and the pair of United States 3c stamps prepays the 6c trans-continental rate in effect at this time.

The 2c Missionary cover does not bear a year-dated marking, but can be reliably dated to 1852. The sender, William Dawson, sailed from San Francisco to the Hawaiian Islands on the schooner Samuel Roberts, which departed on March 10, 1851. His first letter from Hawaii (see Part 2, lot 2073) was written from Lahaina on April 19, 1851, in which he remarks, "I have cast my anchor on this Island & settled down in peace after having been tossed on the tumultuous Waves of Life for Thousands of Miles & have come to the end of my journey. Thus, his correspondence with family and friends back home begins in April 1851.

Further evidence of 1852 usage is provided by the United States stamps and the San Francisco postmark. The 3c pair comes from Plate 2 Late, which is known used as early as January 1852, and the Brownish Carmine shade and impression are typical of the 1852 printings and in stark contrast to the Rose Red shades circulating in 1854. The San Francisco circular datestamp, having a wide font and the letters "Cal." in upper and lower case, came into use in 1849 and is found on covers through early 1853, but no later.

The final factor in determining the year-date is the sailing schedule. The Mary A. Jones sailed from Honolulu on October 5, 1852, the day after the postmark was applied, and arrived in San Francisco on October 26, a voyage of 21 days.