Multiple street fights raged, leaving twenty-two people dead, scores injured, and much property destroyed by fire.

[2] Like other major cities on the Ohio and Mississippi Rivers, Louisville grew rapidly in the previous two decades because of heavy immigration from Ireland and Germany.

[3][4] According to the Louisville Daily Journal by Monday morning the city was "...in possession of an armed mob, the base passions of which were infuriated to the highest pitch by the incendiary appeals of the newspaper organ and the popular leaders of the Know Nothing party.

In the Sixth Ward William Thomasson, a former Congressman from the district, while appealing to the maddened crowd to cease their acts of disorder and violence was struck from behind and beaten.

About 4 o'clock, a vast crowd armed with shotguns, muskets and rifles were proceeding to attack the new German parish of St. Martin of Tours on Shelby street.

Weapons, arms and later bodies of the dead, were stored in Louisville Metro Hall (the old Jefferson County Courthouse, now the Mayor's Office), a Know-Nothing stronghold at the time.

[9] The riots had a profound impact on emigration from Louisville, causing more than ten thousand citizens to pack and leave for good, most to St. Louis, Chicago and Milwaukee, and a large group who left in 1856 for Prairie City, Kansas.

Empty storefronts were the norm on once-bustling commercial corridors and many of the destroyed and charred ruins lay untouched for years afterward, as a silent reminder of that terrible day.

According to journalist Peter Smith, some scholars consider the exodus of immigrants fleeing or avoiding Louisville as having weakened the city economically causing it to be eclipsed by St. Louis and Cincinnati, although others disagree.

According to one of the organizers, Vicky Ullrich, whose German-speaking Swiss ancestors fled to Indiana, "...with another influx of immigrants increasing the diversity of Louisville, it's important that Bloody Monday be remembered so that a similar event does not happen again.