William Thomas Hallenback, Jr., known as Thomas (March 20, 1947 – January 23, 2009), was an American anti-nuclear activist and simple-living adherent who undertook a 27-year peace vigil – the longest recorded vigil in US history at the time, with the title passing to his co-protestor Concepción Picciotto after Thomas' death – in front of the White House. Thomas was born in Tarrytown, New York, and became a truck driver, jewelry maker, and carpenter. Inspired by the Sermon on the Mount, he became a pilgrim and began traveling the world in the interest of world peace.