by the 1830s the american frontier expanded westwards with indian wars in the eastern united states ending. many states let their unorganised militia lapse in favour of volunteer militia units such as city guards who carried on in functions such as assisting local law enforcement, providing troops for ceremonies and parades or as a social club. the groups of company size were usually uniformed and armed through their own contributions. volunteer units of sufficient size could elect their own officers and apply for a state charter under names that they themselves chose.