The US had been conducting studies for a "supersonic transport" (SST) since the early fifties.  Boeing's Model 2707 won a design competition in 1964 against Lockheed's L-2000 for an American SST, but the development program was terminated in 1971 in recognition of the lead already enjoyed by the Tu-144 and Concorde. 

Meanwhile, something else was taking center stage.  The Soviet Space Program had been scoring a steady stream of technological firsts since Sputnik in 1957.  The "giant leap for mankind" on Mare Tranquillatis took place 201 days after the Tu-144 first flew.  Eyes were glistening with pride on both sides of the Iron Curtain. From that point forward, there would be no problems that could not be solved by technology. "Bring on cancer," someone exulted.

The challenges of supersonic flight are immense. Upwards of 50 tons of engine thrust are required to drive 200 tons of hardware through the sky, overcoming drag, which increases abruptly as the plane accelerates toward what is popularly called the "sound barrier"...

As the technical problems are common, resemblances between the Tu-144 and Concorde are striking (delta wing, drooping nose cone), but there are significant differences in their designs, too (for pitch authority at low speed: a canard in one, shifting fuel inside tanks along the fuselage in the other). 

Try to imagine this: Concorde was forbidden to fly at supersonic speeds over inhabited areas!  Note the exclamation point, the only one in this puzzle.  The thought must have been that by flying high enough, an SST would avoid the most troublesome environmental impact -- sonic boom. 

Concorde had a service ceiling of 60,000 feet MSL.  That's more than eleven miles straight up.  One would surely expect that the inverse square law would apply -- that no airplane flying in the stratospher would be found guilty of spooking farm animals or rattling school windows.  Such a happy notion was demolished when test flights of the North American B-70 Valkyrie were carried out in the mid-1960s, not to mention the Operation Bongo fiasco about that time.  Bummer.

In the sketch above, we see the characteristic "N-wave" produced by Concorde flying at twice the speed of sound.  An abrupt rise in pressure at the nose results from compression of the air and an abrupt fall in pressure at the tail results from the air returning to its undisturbed state. 

The speed of sound is about 1,100 ft/sec.  At 200 feet in length, the fuselage of Concorde traveling at twice the speed of sound passes a given point in about 90 ms.  Meanwhile, the N-wave from that point in the sky moves outward in a circular ring at the speed of sound, forming a shock cone, which diverges from the flight path by 30^o and will be experienced on the ground as a double-boom.

What remedies for the sonic boom would you propose that might enable the world's fastest airliner to fly at supersonic speeds over inhabited areas?