County statistics of the United States in the context of "Orange County, California"

Manhattan is the most densely populated and geographically smallest of the five boroughs of New York City. Coextensive with New York County, Manhattan is the smallest county by area in the U.S. state of New York. Located almost entirely on Manhattan Island near the southern tip of the state, Manhattan is centrally located in the Northeast megalopolis and the urban core of the New York metropolitan area. Manhattan serves as New York City's economic and administrative center and has been described as the cultural, financial, media, and entertainment capital of the world.

Present-day Manhattan was originally part of Lenape territory. European settlement began with the establishment of a trading post by Dutch colonists in 1624 on Manhattan Island; the post was named New Amsterdam in 1626. The territory came under English control in 1664 and was renamed New York after King Charles II of England granted the lands to his brother, the Duke of York. New York, based in present-day Lower Manhattan, served as the capital of the United States from 1785 until 1790. The Statue of Liberty in New York Harbor greeted millions of arriving immigrants in the late 19th century and is a world symbol of the United States and its ideals. Manhattan became a borough during the consolidation of New York City in 1898, and houses New York City Hall, the seat of the city's government. Harlem in Upper Manhattan became the center of what is now known as the cultural Harlem Renaissance in the 1920s. The Stonewall Inn in Greenwich Village, part of the Stonewall National Monument, is considered the birthplace in 1969 of the modern gay-rights movement, cementing Manhattan's central role in LGBTQ culture. Manhattan was the site of the original World Trade Center, which was destroyed during the September 11 terrorist attacks in 2001.

Brooklyn is the most populous of the five boroughs of New York City, coextensive with Kings County, in the U.S. state of New York. Located at the westernmost end of Long Island and formerly an independent city, Brooklyn shares a land border with the borough and county of Queens. It has several bridge and tunnel connections to the borough of Manhattan, across the East River, including the architecturally significant Brooklyn Bridge, and is connected to Staten Island by the Verrazzano-Narrows Bridge.

The borough, as Kings County, at 37,339.9 inhabitants per square mile (14,417.0/km), is the second most densely populated county in the U.S. after Manhattan (New York County), and the most populous county in the state, as of 2022. In the 2020 United States census, the borough had a population of 2,736,074. Had Brooklyn remained an independent city on Long Island, it would now be the fourth most populous American city after the rest of New York City, Los Angeles, and Chicago. With a land area of 69.38 square miles (179.7 km) and a water area of 27.48 square miles (71.2 km), Kings County, one of the twelve original counties established under British rule in 1683 in the then-province of New York, is the state of New York's fourth-smallest county by land area and third smallest by total area.

San Diego County (/ˌsæn diˈeɪɡoʊ/ ), officially the County of San Diego, is a county in the southwest corner of the U.S. state of California, north to its border with Mexico. As of the 2020 census, the population was 3,298,634; it is the second-most populous county in California and the fifth-most populous in the United States. Its county seat is San Diego, the second-most populous city in California and the eighth-most populous in the United States. It is the southwesternmost county in the 48 contiguous United States, and is a border county. It is home to 18 Indian reservations, the most of any county in the United States. There are 16 military installations of the U.S. Navy, Marine Corps, and Coast Guard in the county.

San Diego County comprises the San Diego–Chula Vista–Carlsbad, CA Metropolitan Statistical Area, which is the 18th most populous metropolitan statistical area and the 18th most populous primary statistical area in the United States. San Diego County is also part of the San Diego–Tijuana region, the largest metropolitan area shared between the United States and Mexico. From north to south, San Diego County extends from the southern borders of Orange and Riverside counties to the Mexico–U.S. border and the municipalities of Tijuana and Tecate in Baja California. From west to east, San Diego County stretches from the Pacific Ocean to its boundary with Imperial County, which separated from it in 1907.

Manhattan is the most densely populated and geographically smallest of the five boroughs of New York City. Coextensive with New York County, Manhattan is the smallest county by area in the U.S. state of New York. Located almost entirely on Manhattan Island near the southern tip of the state, Manhattan is centrally located in the Northeast megalopolis and the urban core of the New York metropolitan area. Manhattan serves as New York City's economic and administrative center and has been described as the "capital of the world."

Present-day Manhattan was originally part of Lenape territory. European settlement began with the establishment of a trading post by Dutch colonists in 1624 on Manhattan Island; the post was named New Amsterdam in 1626. The territory came under English control in 1664 and was renamed New York after King Charles II of England granted the lands to his brother, the Duke of York. New York, based in present-day Lower Manhattan, served as the capital of the United States from 1785 until 1790. The Statue of Liberty in New York Harbor greeted millions of arriving immigrants in the late 19th century and is a world symbol of the United States and its ideals. Manhattan became a borough during the consolidation of New York City in 1898, and houses New York City Hall, the seat of the city's government. Harlem in Upper Manhattan became the center of what is now known as the cultural Harlem Renaissance in the 1920s. The Stonewall Inn in Greenwich Village, part of the Stonewall National Monument, is considered the birthplace in 1969 of the modern gay-rights movement, cementing Manhattan's central role in LGBTQ culture. Manhattan was the site of the original World Trade Center, which was destroyed during the September 11 terrorist attacks in 2001.