On 17 June 1775 he commanded the left flank of the British assault in the Battle of Bunker Hill. On 9 July he was colonel in the 55th Regiment of Foot. He was promoted to the permanent grade of colonel for his bravery in the battle of Bunker Hill. He was made a major general in 1777. Pigot was placed in command in Rhode Island and made a lieutenant general in 1782. In the Battle of Rhode Island he fought with 3,000 men against 5,000 men under General John Sullivan. He inherited the baronetcy of his older brother Lord George Pigot (it had been created with special remainder) and the Patshull Hall estate in 1777. He also inherited a one-third share of the Pigot Diamond, which remained in the family until sold in a lottery in 1801. On 8 February he resigned and died 1 August 1796 in Stafford, England.