[1] Indigenous trade routes existed in the region going from Prince William Sound to the north of the Alaska Range into the Alaskan Interior starting at least 5000 years ago.

The majority of the trade was facilitated by the Ahtna, but also included the Eyak and Sugpiaq to the south, and the Tanana Athabaskans to the north.

[6]: 6–10  They would eventually cross Isabel Pass, who were also the first recorded non-natives through that route, but fell short 15-20 miles from the Tanana River.

By 1899, the Army ordered Captain Abercrombie to build a military road from Valdez to Copper Center then onto Eagle.

Before winter of 1899, they had completed a 93 mile trail suitable for packhorses through Keystone Canyon and past Thompson Pass to the Tonsina River.

One way message times were generally around 6 months from the Yukon to Washington, D.C.[6]: 12  By 1904, the completion of the WAMCATS allowed near instantaneous communication from Fort Egbert to the US Capitol using an all American telegraph system.

Most traffic using this route was during the winter with pack trains or sled dogs, since animals would tear up moss if it wasn't frozen, hampering travel.

[citation needed] Although automobiles and motorcycles were shipped to Fairbanks and Valdez sometime after 1908, it is unknown when the first motorized vehicle was used on the highway.

A second vehicle made by the White Motor Company from the Alaska Road Commission with representatives manufacturer left the day before Bobby Sheldon's party, and arrived in Fairbanks on August 6th.

[citation needed] The Alaska and Glenn highways, built during World War II, connected the rest of the continent and Anchorage to the Richardson Highway at Delta Junction and Glennallen respectively, allowing motor access to the new military bases built in the Territory just prior to the war: Fort Richardson in Anchorage, and Fort Wainwright adjacent to Fairbanks.

The bridge at Big Delta, the last remaining gap, was built as part of the Alaska Highway project.

[citation needed] The southern end was only open during summers until 1950, when a freight company foreman who lived near the treacherous Thompson Pass plowed the snow himself for an entire season to prove the route could be used year-round.