Leverett was a popular leader of the colonial militia, something that resulted in an unusual situation caused by the colony's militia laws. The colony had voted to limit the size of its militia companies, and restricted their officers to hold only one post. In 1652, when Leverett was captain of a Suffolk County company of horse, he was also elected as a captain of one of Boston infantry companies as well as captain of the Artillery Company of Massachusetts. The colonial magistrates refused to grant him an exemption from the rule, and he was required to give up the Boston post. He was, apparently, allowed to retain his captaincy of the Artillery Company as the company was exempt from regulations governing the militia.