At first, they enforced Lotho's new laws and plans regarding the Shire and persecuted and imprisoned those who would not go along with them, but after his murder they followed Sharkey's commands alone. Being rather unintelligent and not very numerous, after a couple of skirmishes with hobbit country-folk they were defeated at the Battle of Bywater at the end of the War of the Ring and buried in a place known as the Battle Pit.
It is possible that some of these Men had Orc-blood as with the Half-orcs and possibly like the Squint-eyed Southerner was suspected to have. In the Scouring of the Shire some of these men are indeed said to be Half-orc. Aragorn also suggests that they were as well in the Two Towers.