In 1855, Fernando Wood was inaugurated as the first mayor from Tammany Hall, beginning a time in the history of New York City notable for its domination by that institution. Reforms led to the New York City Police Riot of June 1857. There was chaos during the American Civil War, with major rioting in the New York Draft Riots. The Gilded Age brought about prosperity for the city's upper classes amid the further growth of a poor immigrant working class, as well as an increasing consolidation, both economic and municipal, of what would become the five boroughs in 1898.

Oceangoing steamships and steam railroads, developed in earlier decades, grew to take over most long-distance transport, bringing an ever-increasing stream of immigration and industrialization.For a visual overview of the era, see Eric Homberger, The historical atlas of New York City: A visual celebration of 400 years of New York City's history (Macmillan, 2005), pp 84-111

==Pre-Civil War==

Police, gangs and violence The new Republican Party in the late 1850s attempted to cut the power of Mayor Fernando Wood and other pro-South Democrats by abolishing the New York City Municipal Police Department in favor of a Metropolitan Police District.James F. Richardson, The New York Police, Colonial Times to 1901 (1970). Resistance resulted in the New York City Police Riot of 1857. While the police were busy with their feud, the Dead Rabbits Riot between two gangs in Five Points occurred in July, lasting two days, and was stopped only by intervention of the state militia. It was the worst riot in New York City up to that time.Christopher Adamson, "Tribute, turf, honor and the American street gang: patterns of continuity and change since 1820." Theoretical Criminology (1998) 2#1 pp: 57-84. Historian Tyler Anbinder says the "Dead Rabbit" name "so captured the imagination of New Yorkers that the press continued to use it despite the abundant evidence that no such club or gang existed." Anbinder notes that, "for more than a decade, 'Dead Rabbit' became the standard phrase by which city residents described any scandalously riotous individual or group."Tyler Anbinder, Five Points: the 19th-century New York City neighborhood that invented tap dance, stole elections, and became the world's most notorious slum (2001) pp 285-86.

Historians such as Michael Kaplan and Elliott Gorn have argued that an intensifying highly masculine working-class male identity fostered gangs, brawling, and even homicide and rape, which was fueled by New York City taverns. The emerging male code emphasized physical courage, defiance of authority, and class pride. Irish and German immigrants brought European influences. Sexual harassment of women increased because women were more visible outside the home, as many worked in factories and shops. Women were regarded as depersonalized objects of lewd talk, and gang rapes became an opportunity for male bonding.Peter Adams, The Bowery Boys: Street Corner Radicals and the Politics of Rebellion (2005).

Staten Island Quarantine War From 1800 to 1858, Staten Island was the location of the largest quarantine facility in the United States. Angry residents burned down the hospital compound in 1858 in a series of attacks known as the Staten Island Quarantine War. Although there were no deaths as a result of the attack, the arsonists completely destroyed the hospital compound.

Central Park

As the population grew explosively in Lower Manhattan after 1820, middle-class residents were drawn to the few existing open spaces, mainly cemeteries, to get away from the noises, smells, and chaotic life in the city. Landscape painter Asher Brown Durand and writer William Cullen Bryant, recalling their rural upbringing and the great parks of Europe, advocated the therapeutic value of nature in the overcrowded city.Linda Fischer and Harrison Hunt, "Asher B. Durand, William Cullen Bryant, and the Origins of Central Park," New York Journal of American History (2007) 66#4 pp 93-100. Along with architect Andrew Jackson Downing, they envisioned a great park. The state government in 1853 provided $5 million and eminent domain powers to buy out the land owners of what became Central Park. Egbert L. Viele drew the original plans, but Frederick Law Olmsted and Calvert Vaux made the final Greensward Plan design and have received the main credit.Burrows and Wallace, Gotham pp 790-95

Several American influences came together in the design. Landscaped rural cemeteries, such as Mount Auburn in Cambridge, Massachusetts, and Green-Wood Cemetery in Brooklyn, provided examples of idyllic, naturalistic landscapes. The most influential innovations in the Central Park design were the multiple circulation plans for pedestrians, horseback riders, and pleasure vehicles. The crossing routes for commercial traffic were concealed in sunken roadways screened with densely planted shrub belts so as to maintain a natural setting. It was the nation's first great urban park; Olmsted taught Americans a new sensibility in park environments and urban planning as an applied science with his radically naturalistic park design.Eugene P. Moehring, "Frederick Law Olmsted and the Central Park 'Revolution'" Halcyon: A Journal of the Humanities (1985) 7#1 pp 59-75.

Civil War

Prior to the Civil War, in 1861, Mayor Wood proposed that New York City secede from the United States as a neutral sovereign city-state called Free City of Tri-Insula as a way to avoid the ravages of war. Despite strong local Copperhead sympathies, the proposal was not well received.

The city provided a major source of troops, supplies, equipment, and financing for the Union Army. Powerful New York politicians and newspaper editors helped shape public opinion toward the war effort and the policies of President Abraham Lincoln. The port of New York, a major entry point for immigrants, served as recruiting grounds for the Army.Edward K. Spann, Gotham at War: New York City, 1860-1865 (2002) In July 1863, Irish Catholic protestors of conscription began five days of rioting. The "Draft Riots", the worst in American history, targeted blacks and wealthy Republicans. It was suppressed by artillery units of the United States Army firing grapeshot that killed and wounded hundreds of rioters.Iver Bernstein, The New York City Draft Riots: Their Significance for American Society and Politics in the Age of the Civil War (1990); Barnet Schecter, The Devil's Own Work: The Civil War Draft Riots and the Fight to Reconstruct America (2007); Adrian Cook, The Armies of the Streets: The New York City Draft Riots of 1863 (1982) Months later, the upscale membership of the New York Union League Club recruited over 2,000 black men for the 20th United States Colored Infantry to help fill the quotas and to make a major contribution to African American civil rights.Thomas L. Jones, "The Union League Club and New York's First Black Regiments in the Civil War," New York History (2006) 87#3 pp 313-343William Seraile, New York's Black Regiments During the Civil War (2015) The neighboring city of Brooklyn was more consistently pro-war.E. H. Livingston, President Lincoln's Third Largest City: Brooklyn and The Civil War (1994)

In 1865 the Metropolitan Fire District united the fire departments of New York and Brooklyn, and was more successful than the earlier Metropolitan Police District, eventually developing into the New York City Fire Department.Jackson, Encyclopedia of New Your City (2010) p 452

Tourism and entertainment

New York increasingly became the national capital for the rapidly expanding tourism and entertainment industries. Steamships and railways brought not just immigrants and businessmen but tourists, and grand hotels were built for upscale visitors.Justin Kaplan, When the Astors Owned New York: Blue Bloods and Grand Hotels in a Gilded Age (2006). New York's theater district gradually moved northward during this half century, from the Bowery up Broadway through Union Square and Madison Square, settling around Times Square at the end of the 19th century. Edwin Booth and Lillian Russell were among the Broadway stars.Lewis A. Erenberg, Steppin'Out: New York Nightlife and the Transformation of American Culture (1984) Prostitutes served a wide variety of clientele, from sailors on leave to playboys.Timothy J. Gilfoyle, City of eros: New York City, prostitution, and the commercialization of sex, 1790–1920 (1994).

The first nightclubs appeared in New York City in the 1840s and 1850s, including McGlory's, and the Haymarket. They enjoyed a national reputation for live music, dance, and vaudeville acts. They tolerated unlicensed liquor, commercial sex, and gambling cards, chiefly Faro. Practically all gambling was illegal in the city (except upscale horseracing tracks), and regular payoffs to political and police leadership was necessary. Prices were high and they were patronized by an upscale audience. Timothy Gilfoyle calls him "the first nightclubs."Timothy J. Gilfoyle, "Scorsese's Gangs of New York: Why Myth Matters." Journal of Urban History 29.5 (2003): 620–630 at p. 624.Burrows and Wallace, Gotham (1999) 1148 By contrast, Owney Geoghegan ran the toughest nightclub in New York, 1880–83. It catered to a downscale clientele and besides the usual illegal liquor, gambling and prostitution, it featured nighly fistfights, and occasional shootings, stabbings, and police raids.Lewis A. Erenberg, Steppin' Out: New York Nightlife and the Transformation of American Culture, 1890–1930 (1981). Webster Hall is credited as the first modern nightclub. It opened in 1886 as a "social hall", originally functioning as a home for dance and political activism events.

Gilded Age

The post-war period was noted for the corruption and graft for which Tammany Hall has become proverbial, but equally for the foundation of New York's pre-eminent cultural institutions, the Metropolitan Museum of Art and the Metropolitan Opera. The Brooklyn Museum was a major institution of New York's independent sister city. Various older institutions merged into the New York Public Library. The New York Academy of Sciences, founded early in the century, expanded and promoted other institutions such as the New York Botanical Garden and the American Museum of Natural History.

New York newspapers were read across the nation, particularly, the New York Tribune, edited by Horace Greeley, the voice of the new Republican Party.Jeter Allen Isely, Horace Greeley and the Republican Party, 1853-1861: A Study of the New York Tribune (1947)

As immigration increased in cities, poverty rose as well. The poorest crowded into low-cost housing such as the Five Points and Hell's Kitchen neighborhoods in Manhattan. These areas were quickly overridden with notorious criminal gangs such as the Five Points Gang and the Bowery Boys. Overcrowding spread germs; the death rates in big city tenements vastly exceeded those in the countryside.Tindall, George Brown and Shi, David E. America: A Narrative History (Brief 9th ed. 2012) vol 2 p. 590

Rapid outward expansion required longer journeys to work and shopping for the middle class office workers and housewives. The working class generally did not own automobiles until after 1945; they typically walked to nearby factories and patronized small neighborhood stores. The middle class demanded a better transportation system. Slow horse-drawn streetcars and faster electric trolleys were the rage in the 1880s.

In the horse-drawn era, streets were unpaved and covered with dirt or gravel. However, this produced uneven wear, opened new hazards for pedestrians, and made for dangerous potholes for bicycles and for motor vehicles. Manhattan alone had 130,000 horses in 1900, pulling streetcars, delivery wagons, and private carriages, and leaving their waste behind. They were not fast, and pedestrians could dodge and scramble their way across the crowded streets. Traffic injuries and deaths were mostly caused by horses escaping control.