In April 1840 a report of a planned revolt against Alvarado by a group of foreigners, led by former ally Isaac Graham, caused the governor to order their arrest and deportation to Mexico City for trial. They were eventually, however, acquitted of all charges in June 1841. Also in 1841, political leaders in the United States were declaring their doctrine of Manifest Destiny, and Californios grew increasingly concerned over their intentions. Vallejo conferred with Castro and Alvarado recommending that Mexico send military reinforcements to enforce their military control of California.