In 1942, the Astors gave Cliveden to the National Trust with the proviso that the family could continue to live in the house for as long as they wished. Should they cease to do so, they expressed the wish that the house be used "for promoting friendship and understanding between the peoples of the United States and Canada and the other dominions." With the gift of Cliveden, the National Trust also received from the Astors one of their largest endowments (£250,000 in 1942 which is equivalent to £10,809,375 in 2016).