Father and son continued their work in the Latin School until it was closed in April 1775, during the Siege of Boston in the American Revolutionary War.While the school produced a number of revolutionary leaders, including John Hancock and Samuel Adams, the approaching revolution split father and son.John Lovell wrote and endorsed Loyalist or Tory positions, while James became aligned with the Whigs and associated growing rebel sentiment.James was transported with the British fleet as a prisoner and taken to Halifax, Nova Scotia, where he spent nine months in the jail.This reached its peak when Gates was given command of the Northern Department, replacing Philip Schuyler in the summer of 1777.After graduating from Harvard in 1776, he joined the 16th Massachusetts regiment as a lieutenant and saw action at Battle of Monmouth and in Rhode Island.