3 states · Census division · 42,492,943 people · 109,332 sq mi
Middle Atlantic states map
The Middle Atlantic division is New York, New Jersey and Pennsylvania — three states with more people than the twenty-two least populous states put together.
How the region is defined
"Middle Atlantic" is the Census Bureau's name for the division of the Northeast region that is not New England: New York, New Jersey and Pennsylvania. It should not be confused with the informal Mid-Atlantic, which usually adds Delaware, Maryland, Washington, DC and sometimes Virginia; the Census assigns those to the South Atlantic division.
The three states had 42,492,943 residents in 2020 on 109,332 square miles. New York City alone (8,804,190) has more people than 38 individual states, and Philadelphia (1,603,797) is the sixth-largest US city. New Jersey is the most densely populated state in the country, with about 1,260 people per square mile.
States, capitals and largest cities
| State | Capital | Largest city | Population (2020) | Area (sq mi) |
|---|---|---|---|---|
| New Jersey (NJ) | Trenton | Newark | 9,288,994 | 8,723 |
| New York (NY) | Albany | New York City | 20,201,249 | 54,555 |
| Pennsylvania (PA) | Harrisburg | Philadelphia | 13,002,700 | 46,054 |
| Total (3 states) | 42,492,943 | 109,332 |
Geography
The three states span from the Atlantic to Lake Erie. The Atlantic coastal plain covers all of southern New Jersey and Long Island; the Piedmont and the Appalachian ridges take up most of Pennsylvania; and the Allegheny Plateau covers western Pennsylvania and the Southern Tier of New York. The Adirondacks of northern New York, where Mount Marcy (5,344 ft) is the state's high point, are geologically part of the Canadian Shield rather than the Appalachians. Pennsylvania's high point, Mount Davis, is only 3,213 ft.
The Hudson River runs 315 miles from the Adirondacks to New York Harbor. The Delaware River forms New Jersey's whole western border and Pennsylvania's eastern one, and the Susquehanna crosses Pennsylvania on its way to Chesapeake Bay. In the west the Allegheny and Monongahela meet at Pittsburgh to form the Ohio. New York touches two Great Lakes — Erie and Ontario — joined by the Niagara River and Niagara Falls; Pennsylvania has a 50-mile shore on Lake Erie.
The Mason–Dixon line along Pennsylvania's southern border separates the division from Maryland, West Virginia and Delaware. All three states are on Eastern time. Pennsylvania (67 counties) and New York (62) are large enough that the state capitals — Harrisburg and Albany — are 100 and 150 miles from the largest cities.
Related maps
- Parent region: Northeast; sibling division New England.
- Broader informal grouping: Mid-Atlantic.
- Quiz: Northeast states quiz.
- Cities: New York, Philadelphia, Pittsburgh; capitals Albany, Trenton, Harrisburg.
- Geography: Hudson River, Appalachians, Mason–Dixon line.