To the best of my knowledge, the "Broom Brigades" were ostensibly
non-political groups of young women who drilled with brooms as if the brooms
were rifles. The fad peaked before 1885.

The whole notion of "broom brigades" screams of sexual titillation arising
from of gender role reversals (women doing military drills) within gender
stereotypes (drilling with a tool for women's work). I image they appeared
much like the precision lawn chair drill teams of more recent era, but not
quite so obviously farcical.

From:
Mark Twain  _Life on the Mississippi_  (1883)
(chapter 44)

seen in New Orleans

"In the West and South they have a new institution--the Broom Brigade.
It is composed of young ladies who dress in a uniform costume,
and go through the infantry drill, with broom in place of musket.
It is a very pretty sight, on private view.  When they perform
on the stage of a theater, in the blaze of colored fires,
it must be a fine and fascinating spectacle.  I saw them go through
their complex manual with grace, spirit, and admirable precision.
I saw them do everything which a human being can possibly do with a broom,
except sweep.  I did not see them sweep.  But I know they could learn.
What they have already learned proves that.  And if they ever
should learn, and should go on the war-path down Tchoupitoulas
or some of those other streets around there, those thoroughfares
would bear a greatly improved aspect in a very few minutes.
But the girls themselves wouldn't; so nothing would be really gained,
after all."