Despite its origins, the Lewis gun was not initially adopted by the U.S. military, most likely because of political differences between Lewis and General William Crozier, the chief of the Ordnance Department.
Trods dens oprindelse blev Lewis maskingeværet ikke indført i det amerikanske militær fra begyndelsen - formentlig på grund af politiske uoverensstemmelser mellem Lewis og General William Crozier, chefen for våbenafdelingen.