Since I live in the Seattle metropolitan area and have lived within walking distance of the Boeing Everett Assembly Plant, I think that I should mention that the SST is known as the "airplane that almost ate Seattle."
By the end of the 1960s, the Apollo project was winding down and Boeing hoped to increase sales of commercial aircraft to make up for the decrease of space-related business. Unfortunately, due to the recession in the aviation industry, Boeing went 18 months without a single new domestic airplane order. The 747 had not yet established itself in the market and had unexpectedly high startup costs and initial delivery problems.
The end of the SST program dealt another blow to Boeing. Aided by federal funds, Boeing had made major progress, but Congress "pulled the plug" on SST funding in March 1971, forcing Boeing to cancel the program.
In the Seattle area alone, the Boeing workforce was cut from 80,400 to 37,200 between early 1970 and October 1971. Thousands of former Boeing employees, finding little in the local job market, looked for work outside the region. Things looked so bleak that on April 16, 1971, real-estate agents Bob McDonald and Jim Youngren put the words, "Will the last person leaving SEATTLE -- Turn out the lights" on a billboard at S 167th Street and Pacific Highway S near Sea-Tac International Airport.
For many years, Seattle had the nickname "Jet City" because of the importance Boeing played in the economy of the Seattle metropolitan area. The region's prosperity was tied to Boeing's. The late Seattle NBA franchise was originally named Super Sonics, before being shortened to Sonics, for the SST program. Thankfully, the region's economy has diversified with Microsoft, Starbucks, Amazon and other companies.