After months of intense debate, Congress finally passed the Kansas-Nebraska Act on May 30, 1854, largely along sectional lines. Over the next several years Kansas Territory became "Bleeding Kansas" as violence erupted between pro-slavery and free-state factions. While scholars continue to debate the true causes of the fighting in Kansas, there is a strong consensus that the conflict was fundamentally shaped by the national political debate over the extension of slavery--if not by the slavery issue itself. Bleeding Kansas occurred at a time when one type of vigilante group, the "claim club," was becoming widespread across not only Kansas but also in places such as Iowa, Nebraska, Colorado, Montana, and California.