Editing Amtrak (section)

===Routes===
{{Main|List of Amtrak routes|List of busiest Amtrak stations|List of major cities in the United States lacking inter-city rail service}}
Amtrak is required by law to operate a national route system.<ref>''Amtrak Reform and Accountability Act of 1997.'' 105th Cong., Senate Report 105-85 (September 24, 1997).</ref> Amtrak has presence in 46 of the 48 contiguous states, as well as the District of Columbia (with only thruway connecting services in [[Wyoming]] and no services in [[South Dakota]]). Amtrak services fall into three groups: short-haul service on the Northeast Corridor, state-supported short-haul service outside the Northeast Corridor, and medium- and long-haul service known within Amtrak as the National Network. Amtrak receives federal funding for the vast majority of its operations including the central spine of the Northeast Corridor as well as for its National Network routes. In addition to the federally funded routes, Amtrak partners with transportation agencies in 18 states to operate other short and medium-haul routes outside of the Northeast Corridor, some of which connect to it or are extensions from it. In addition to its inter-city services, Amtrak also operates commuter services under contract for three public agencies: the [[MARC Train|MARC]] [[Penn Line]] in Maryland, [[Shore Line East]] in Connecticut,<ref>{{cite web |title=Shore Line East |url=https://portal.ct.gov/DOT/Traveler/Rail/SLE |access-date=June 19, 2022 |website=CT.gov - Connecticut's Official State Website |language=en |archive-date=October 5, 2022 |archive-url=https://web.archive.org/web/20221005211910/https://portal.ct.gov/DOT/Traveler/Rail/SLE |url-status=live }}</ref> and [[Metrolink (California)|Metrolink]] in Southern California.

Service on the [[Northeast Corridor]] (NEC), between [[Boston]], and [[Washington, D.C.]], as well as between [[Philadelphia]] and [[Harrisburg, Pennsylvania|Harrisburg]], is powered by [[overhead line]]s; for the rest of the system, diesel-fueled locomotives are used. Routes vary widely in the frequency of service, from three-days-a-week trains on the ''[[Sunset Limited]]'' to several times per hour on the Northeast Corridor.<ref>{{cite web |url=http://www.amtrak.com/train-schedules-timetables |title=Amtrak Train Schedules, Timetables |website=Amtrak.com |access-date=November 23, 2012 |archive-date=November 23, 2012 |archive-url=https://web.archive.org/web/20121123035314/http://www.amtrak.com/train-schedules-timetables |url-status=live}}</ref> For areas not served by trains, [[Amtrak Thruway]] routes provide guaranteed connections to trains via buses, vans, ferries and other modes.<ref name=":3">{{cite web |title=Amtrak Thruway Connecting Services Multiply Your Travel Destinations |url=https://www.amtrak.com/thruway-connecting-services-multiply-your-travel-destinations |url-status=live |archive-url=https://web.archive.org/web/20180404220008/http://www.amtrak.com/thruway-connecting-services-multiply-your-travel-destinations |archive-date=April 4, 2018 |access-date=October 2, 2021 |website=Amtrak |language=en}}</ref>

The most popular and heavily used services are those running on the NEC, including the ''[[Acela]]'' and ''[[Northeast Regional]]''. The NEC runs between Boston and Washington, D.C. via New York City and Philadelphia. Some services continue into [[Virginia]]. The NEC services accounted for 4.4&nbsp;million of Amtrak's 12.2 million passengers in [[fiscal year]] 2021.<ref name=":0" /> Outside the NEC the most popular services are the short-haul corridors in California, the ''[[Pacific Surfliner]]'', ''[[Capitol Corridor]]'', and ''[[San Joaquin (train)|San Joaquins]]'', which are supplemented by an extensive network of connecting buses. Together the California corridor trains accounted for a combined 2.35 million passengers in fiscal year 2021.<ref name=":0" /> Other popular routes include the ''[[Empire Service]]'' between New York City and [[Niagara Falls, New York|Niagara Falls]], via [[Albany, New York|Albany]] and [[Buffalo, New York|Buffalo]], which carried 613.2 thousand passengers in fiscal year 2021, and the ''[[Keystone Service]]'' between New York City and Harrisburg via Philadelphia that carried 394.3 thousand passengers that same year.<ref name=":0" />
[[File:South Station Tower arches Jan 2025.jpg|thumb|204x204px|[[South Station|Boston South Station]], the northern end of the Northeast Corridor]]
Four of the six busiest stations by boardings are on the NEC: [[Pennsylvania Station (New York City)|New York Penn Station]] (first), [[Washington Union Station]] (second), [[30th Street Station|Philadelphia 30th Street Station]] (third), and [[South Station|Boston South Station]] (fifth). The other two are [[Chicago Union Station]] (fourth) and [[Union Station (Los Angeles)|Los Angeles Union Station]] (sixth).<ref name="FY18 profile" />