The United States has several major cities. Some of them have [[UsefulNotes/WorldSubways subways]]. Here are the biggest ones.

[[index]]
* UsefulNotes/NewYorkCitySubway
* UsefulNotes/WashingtonMetro
* UsefulNotes/ChicagoL
* UsefulNotes/TheT (Boston)
* UsefulNotes/BayAreaRapidTransit[[/index]] (San Francisco Bay Area) and UsefulNotes/MuniMetro[[index]] (SanFrancisco itself)
* UsefulNotes/PortAuthorityTransHudson (New York and New Jersey)
* UsefulNotes/PhiladelphiaSubways (SEPTA and PATCO)
[[/index]]
* UsefulNotes/MARTASubway (Atlanta)
[[index]]
* UsefulNotes/LosAngelesMetroRail
* UsefulNotes/MiamiMetrorail
* UsefulNotes/BaltimoreMetro
[[/index]]

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