Ultimately, the speed limit fell to 79 mph (127 km/h) in 1968 because of signaling changes, and the scheduled duration went back to 90 minutes end-to-end.

[9] Under Amtrak, which assumed control of most intercity passenger rail service in the United States on May 1, 1971, the Hiawatha name survived in two forms.

On June 15, 1976, Amtrak introduced Turboliners to the route and the name Hiawatha Service left the timetable, not to return until 1989.

[11] A resurfacing project on Interstate 94 led to a three-month trial of service west of Milwaukee to Watertown, Wisconsin beginning on April 13, 1998.

The Canadian Pacific Railway, which owned the tracks through its American subsidiary Soo Line Railroad, estimated that the route would require between $15–33 million in capital investment before it could host the extended service permanently.

[12]: 184 [13][14] Between 2000 and 2001, Amtrak considered extending one Hiawatha round-trip 70 miles (113 km) north from Milwaukee to Fond du Lac, Wisconsin.

Amtrak hoped to attract mail and express business along the route as part of its Network Growth Strategy, similar to the short-lived Lake Country Limited.

[16] The route is coextensive with the far southern leg of the Empire Builder, Amtrak's long-distance service from Chicago to the Pacific Northwest.

It excludes long-distance trains such as the Empire Builder and North Coast Hiawatha whose local stopping patterns were restricted.

The Abraham Lincoln and Prairie State were Chicago-St. Louis services which Amtrak extended through Chicago to the north in the early 1970s.

[citation needed] On July 17, 2009, the State of Wisconsin announced it would purchase two new train sets from Spanish manufacturer Talgo in preparation for the enhanced-speed service that received funding in early 2010.

[44] The two sets built were stored in the former Talgo plant until May 2014, when Amtrak moved them to its maintenance facility near Indianapolis, Indiana.

[46] In August 2019, the Federal Railroad Administration (FRA) awarded WisDOT up to $25.2 million to purchase six new coaches and three new cab cars for the route, allowing the replacement of the NPCUs.

The move grants $500,000 toward studying additional frequency and prioritizes the corridor for future federal funding[51] under the Infrastructure Investment and Jobs Act passed in November 2021.

[52] In 2009, Wisconsin applied for funding from an $8 billion pool allocated for rail projects under the American Recovery and Reinvestment Act, and the Chicago–Milwaukee–Madison–Minneapolis/St.

Another $12 million would have been used to upgrade the line between Chicago and Milwaukee, and an additional $600,000 was granted to study future alignments to the Twin Cities.

The Wisconsin Department of Transportation (WisDOT) dropped Oconomowoc from the planned route in August 2010,[56] and Brookfield was waiting to see the outcome of elections in November before making a decision on whether to build a station.

Republican candidate Scott Walker promised he would stop the project and return the money the state received if elected.

[61] On December 9, 2010, U.S. Transportation Secretary Ray LaHood announced that much of the $810 million that Wisconsin was supposed to get would be redistributed to other states, including California, Florida, and Washington.

[64] There had long been proposals to extend one or more Hiawatha trips from Milwaukee to Minneapolis–Saint Paul, Minnesota, which would double service frequency on the Twin Cities-Milwaukee-Chicago (TCMC) corridor.

A 2015 feasibility report by Amtrak looked at extending one round trip as a "second train" along the route of the Empire Builder through La Crosse.

Annual ridership was forecast between 117,800 and 155,500 if the service ended at Saint Paul Union Depot, and higher if it extended to Target Field, Fridley, or St.

One would complement the Empire Builder, while two would take a new route with stops in Camp Douglas, Eau Claire, Menomonie, and Hudson.

Amtrak has proposed extending three Hiawatha trips from Milwaukee to Green Bay by 2035, with stops in Fond du Lac, Oshkosh, and Appleton.