Stephen Pleasonton was the first "Fifth Auditor" of the U.S. Treasury Department; he is historically significant for his part in saving priceless early government documents from possible destruction, but is chiefly remembered today for his singularly bureaucratic work in overseeing the Treasury Department's Lighthouse Establishment during most of its existence. He was also the father of Union Civil War Generals Alfred Pleasonton and Augustus Pleasonton.

The United States Lighthouse Board was the second agency of the U.S. federal government, under the Department of Treasury, responsible for the construction and maintenance of all lighthouses and navigation aids in the United States, between 1852 and 1910. The new agency was created following complaints of the shipping industry of the previous administration of lighthouses under the Treasury's Lighthouse Establishment, which had had jurisdiction since 1791, and since 1820, been under the control of Stephen Pleasonton.