In 1857, two rival police forces were operating at the same time in one major U.S. city—it did not end well. The unusual situation in New York City was the outcome of a corrupt mayor and opposing political parties heading the state and city governments and would eventually erupt in a bloody, all-out police brawl.

The tensions took root in a city seeped in corruption. The administration of Democratic Mayor Fernando Wood was regularly accused of graft, electioneering, demagoguery and bribery. Despite the mayor’s sleaziness, he had a solid base of support from New York City’s immigrant lower classes, particularly the Irish, who felt that the mayor protected them from a patronizing, anti-immigrant elite class. Mayor Wood’s deliberate failure to enforce temperance laws which would have restricted drinking saloons, made him a hero among the underclass. To help maintain his grip on the city, Wood misused New York’s police as a cudgel to guarantee election results and his power. Many of the police, meanwhile, took part in the graft and bribery common of the era.

However, the recently formed Republican Party, coming into control of the New York State government, strategized a means to break the mayor’s and the Democratic Party’s control over the city. In April 1857, the State Legislature passed a law which disbanded New York’s Municipal Police, ostensibly for corruption and to enforce liquor laws, and replaced it with a State-controlled Metropolitan Police force that encompassed the area of Manhattan, then independent Brooklyn, Staten Island, and Westchester County. Wood claimed the new police was illegal since it violated the principle of home rule, and sued. A decision would not be made for months.

In the meantime, Wood’s Municipal force and the State’s Metropolitans were operating in the same city at the same time. At the various station houses throughout the city, roll calls were taken and individual policemen were to announce their support— either to Wood or to the State. Fifteen police captains remained loyal to Wood, and only about 300 of the 1,100 rank-and-file police joined the new police. Each side dismissed those police who were not loyal and filled the vacancies by appointing new officers.

With the stage set for conflict, the two forces often competed with each other. In one instance, for example, a man arrested for drunken and disorderly conduct refused to recognize the Metropolitans arresting him as officers and only gave himself up when a Municipal came on the scene. This resulted in a nasty melee between the two forces and a near riot.

The situation came to a head on the morning of June 16 when Daniel Conover went to City Hall to assume the office of Street Commissioner. He was appointed by Governor John King, an enemy of Wood and one of the chief Republicans responsible for the new police law. The mayor objected to Conover’s appointment, claimed the governor had no power to do so, and named his own designee for the office, Charles Devlin—a prominent city works contractor.

The position of Street Commissioner was highly lucrative and filled with vast opportunities for graft. Neither side would back off, so Mayor Wood ordered Conover removed from City Hall. This was done forcibly and with some violence. The incensed Conover then obtained warrants for arrest against Wood for personal injury and inciting a riot which was given to a Metropolitan Police captain to execute. The captain went to City Hall and was admitted into Wood’s private office. The mayor, holding his staff of office, refused to recognize the captain as an officer of the law. The officer attempted to seize the mayor, but since Wood had filled City Hall with his Municipals, he found himself removed from the mayor’s office and deposited into the hallway.

Meanwhile, word of the confrontation spread quickly. A mob of Wood supporters arrived at City Hall Park of whom the diarist George Templeton Strong described as a “miscellaneous assortment of suckers, soaplocks, Irishmen and plug uglies officiating in a guerrilla capacity.” Gawkers stood on roofs from the surrounding buildings, waiting for the anticipated explosion of violence. Mayor Wood reinforced City Hall with several hundred Municipals and locked the building.

At 3:30 pm, a phalanx of 50 Metropolitans marching two abreast under the command of Coroner Frederick W. Perry and Captain Jacob Sebring entered the park. The Metropolitans were in full uniform with frock coats and newly minted badges. Each of their plug hats was decorated with a ribbon labeled “Metropolitan Police” and their officer number. They brandished batons—nearly 12-inch clubs which were their primary tools for law enforcement. Perry was to deliver the warrant and arrest the mayor.

The mob heckled the Metropolitans while cheering for Fernando Wood. Some shouted, “Here they come; pitch into the sons of bitches.” Some broke off branches to use as weapons. Some brandished brickbats. Some gathered stones. And some climbed into the park’s trees for a better view.

Shoving the crowd aside, Sebring led his men toward the rear entrance of City Hall. As they pushed up the 20 steps to the stoop of the entryway, they encountered about 30 Municipals guarding the entrance. Shoving and arguing began, then, out of a side door rushed a reinforcement of Municipals brandishing their clubs. The Metropolitans were flanked front and side with an angry mob behind them. They did not stand a chance.

The Metropolitans were driven back down the stairs, but not from the field. Sebring formed his men and charged up the stairs to take the doors by storm. Coroner Perry almost made it inside before he was roughly pushed off the stoop. Again, the Municipals, in far superior numbers and having tactical advantage, attacked. Wounded men rolled down the stairs and blood dripped down the railings of City Hall. The Metropolitans fled the field with the Municipals and the mob chasing after them. Some estimates give 53 men wounded in the brawl.

Wood may have won the battle but not the war. The violence was settled later in the day by the 7th regiment of the National Guard, which happened to be marching down Broadway en route to the harbor. They were appealed to intervene by Metropolitan supporters. The mayor was arrested then quickly released. Wood and the governor called a truce and agreed to let both forces patrol the city uninterrupted until the mayor’s appeal was settled in court.

Wood’s Municipal Police were finally disbanded when the New York Court of Appeals ruled in the State’s favor on July 2. But the lawlessness through the period led to one of the most notorious riots in New York City history, the “Dead Rabbits Riot” over the July 4 weekend, which presaged the infamous New York City Draft Riots of 1863. George Templeton Strong opined that there was no victory in the police controversy since the outcome would only decide “which horde had the legal right to be supported by the public plunder.”

Joseph A. Williams is the author of The Sunken Gold: A Story of World War I, Espionage, and the Greatest Treasure Salvage in History and Seventeen Fathoms Deep: The Saga of the Submarine S-4 Disaster.