Unlike Western Europe amd East Asia, North America does not have a high-speed rail system, other than the Acela in Northeast corridor, which is slower than other HSR systems throughout the world. Has there been any reasons why these countries never built HSR, especially in areas like the Northeast corridor, California, and Windsor-Quebec City corridor, where population density is more rail-friendly? Were there any major pushes to build HSR throughout the second half of the 20th century or has it never gotten ,uch political traction?
Well, the history of the quest for speed in North American railroads is a long one.
The simplified version, perhaps a blend of ELI5 and AskHistorians follows.
The 19th century ended with a handful of railroads around the country operating fast enough equipment over track capable to handle trains over 100mph. The CB&Q (Chicago, Burlington & Quincy), the New York Central, and the Pennsylvania were shining examples of railroads that regularly operated trains over 100 miles an hour by 1900.
In competition with "Steam" railroads of the era, the exploding fad of interurban electric railways, connecting towns and cities across the US gave rise to fast, clean and punctual service between metropolitan areas. Famous among these is the Cincinatti & Lake Erie "Red Devil" interurban racing a biplane in 1930 at a blazing 97mph, winning along its route. https://en.wikipedia.org/wiki/Red_Devil_(interurban)
RAILROADS:
The CB&Q Did this to cut time across the vast distances on its billiard table flat Midwest plains routes, later dubbed the route of the Zephyrs with its gleaming diesel streamliners of the same name. They operated 110mph in many stretches of their passenger routes that crisscrossed the Midwest. http://www.burlingtonroute.com/image/map.jpg
The PRR and NYC duked it out in many markets, but especially between the very valuable New York City > Chicago route. Dubbed the "Water Level Route" by the NYC, the fiercely competitive rivals developed more powerful and more glamorous trains and locomotives to vie for the rich and famous, culminating in the very fast 20th Century Limited on the New York Central and the Broadway Limited on the Pennsy. Trial runs boasted speeds of 123 mph on the 20th century in 1938. In this YT video, around 0:18 you can see the Maginificent 4-6-4 Husdon fly by at over 100mph. https://www.youtube.com/watch?v=Ud9iKostUIc
Out west the Atchinson, Topeka & Santa Fe, the Union Pacific and the Milwaukee Road all fought over three of the ways west from Chicago to Los Angeles, San Francisco, and Portland-Seattle respectively. They all used ATS to ensure 90+ mph service across great stretches of the west, often exceeding 100+ mph in stretches of tangent (straight) track. Here's a video of the Santa Fe Super Chief circa 1952. https://www.youtube.com/watch?v=Dl_LoQ4vHDc
The Illinois Central's "City of New Orleans" boasted 100+ mph scheduled(!) performance between Chicago & NOLA in some stretches.
Anyways, after WWII, the short haul airlines colluded together to bring a bill to congress to limit the operational speed of passenger trains in the US to 79mph unless various expensive signaling improvements were made. (If someone knows the EXACT bill that limited this speed, PLEASE let me know, I've been digging through records trying to find it)
The development, and requirement of ATS (Automatic Train Stop) to prevent high speed derailments was required by the ICC to run above 79mph.
This speed restriction still stands today on much of the modern post 1971 AMTRAK system, with notable exceptions around the country like the Northeast Corridor.
LBJ in the late 60's pushed as part of his "Great Society" initiative to explore higher speed trains. This developed the Budd "Metroliner" service between NYC and Washington DC, and helped along the development of the United Aircraft Corp "TURBOTRAIN" which was designed to operate at 170mph! https://en.wikipedia.org/wiki/UAC_TurboTrain
THE WHY:
Sources: "The Men Who Loved Trains" (Rush Loving) "TRAINS" Magazine April 2014 "The Interurban Era" (Middleton) "The Age of Steam" (Beebe)