Election day, Aug. 6, 1855, known as Bloody Monday due to riots led by “Know-Nothing” mobs. This political party was anti-Catholic and nativist. Attacks on German immigrants east of downtown and Irish in the west caused at least 22 deaths, arson, and looting. Catholic Cathedral of the Assumption & St. Martin’s Church were threatened with destruction. American (Know-Nothing) Party. This party feared that Catholic immigrants from Germany and Ireland threatened Protestantism and democracy. By 1854, the party claimed a million members nationwide and led Jefferson Co. govt. They split over slavery and by the end of the Civil War they had vanished from politics in Louisville and Jefferson Co., Kentucky.