New York City had an estimated 25,000 residents on the eve of the Revolution, and was the second largest city in the colonies, after Philadelphia. It had long outgrown the old boundaries of New Amsterdam, and extended almost a mile from the tip of Manhattan, just past the old city commons (laid out as a public space in 1686, it now houses City Hall and City Hall Park) and on the sides of the Collect Pond, the largest watercourse in lower Manhattan. Most of the homes and businesses in the city were located on the eastern side of the island, as the docks and wharves were all located there (some ritzy mansions had been built on the west side of Broadway, but much of the surrounding land was not heavily built up). Here is a map done by surveyor Francis Maerschalk in 1763, and here is another done by Lieutenant Bernard Ratzer in 1767, that show the layout of the city in the years before the war.

Of the 25,000 residents, a majority of them fled the city between the end of 1775 and summer of 1776, when the British anchored their fleet off of Staten Island (a bastion of Loyalists). The British had a force of 32,000 British soldiers and Hessians, and 13,000 sailors. It is estimated that on the eve of the Battle of Brooklyn, the largest single engagement in the entire war, there were an estimated 5,000 residents left in the city, along with the American troops, numbering around 23,000 between Manhattan and Brooklyn. After the Battle of Brooklyn and the Battle of Harlem Heights, most of Manhattan was left in the hands of the British, and the city’s population started to increase as Loyalists poured in. The British captured Fort Washington in November, 1776, and controlled the whole island for the duration of the war.

By early 1777, there were 12,000 civilians in New York, in addition to the 5,000 British troops. Two years later, the population of the city had grown tremendously, with 33,000 civilians and 10,000 soldiers. A disastrous fire had broken out in September, 1776, and it spread quickly throughout the city, burning at least 493 buildings (some accounts put the number closer to 1,000, which was the quarter of the structures in the city). The British did not rebuild them during the course of the war, which led to a massive housing shortage (here is a view of the ruins of Trinity Church in 1780). British officers were quartered in the city’s mansions (the Kennedy House at 1 Broadway was used by General Clinton, and the Beekman Mansion far outside of the city was used by General Howe), and hobnobbed with moneyed Loyalists, holding resplendent balls and lavish feasts. However, the majority of soldiers living in the city were housed in cramped conditions. A tent city, known as “canvas town,” sprang up on the west side, and became the haunt of ne'er do wells and prostitutes (since the 1760s, the area behind Trinity Church had been the city’s red light district, known as the “Holy Ground”).

George Washington had plans to retake the city (French troops had landed in Rhode Island to help in this endeavor), but his Generals convinced him that his efforts were best directed elsewhere. Following the surrender at Yorktown, Loyalists started to leave New York in droves. In 1782 and 1783, between 29,000 and 32,000 people left the city, with three-quarters of them sailing for Canada. At the same time, Americans flooded into the city, which soon had a population of 12,000. On November 25rd, 1783, the last of the British troops left the city, and Washington victoriously entered, surrounded by his troops and cheering Americans. The soldiers went to hoist up the American flag over the Battery, and found that the British had greased the pole. John Van Arsdale, a sailor, donned a pair of cleats and scaled the pole, removing the British flag and replacing it with the stars and bars as the last of the British fleet sailed away.

I hope that gives you a better idea of what the city looked like during the American Revolution. Let me know if you have any other questions!