I checked out the page, and have to disagree with some of the author's conclusions.
1. A 'vacuum' is the absence of pressure, not the absence of matter, so some amount of streamlining is required for all high-velocity craft.
2. The theoretical speed of 14,000 mph is possible, but doesn't translate to crossing the US in 21 minutes, because you have to account for time spent accelerating & decelerating. A maximum speed in the vicinity of 21,000 mph would have to be attained mid-course to allow for reasonably comfortable G-forces.
3. Odds are that the 'Taos Hum' could be caused by ELF communications; construction on the system was started in the mid-1970's, and it's been operational since the early- to mid-1980's. This system does cross the continental United States, and is the only known example of fully-applied, operational Tesla technology.
4. The TBM with the USAF markings was part of the Peacekeeper ICBM Program; the sign above the not-yet-bored tunnel bears the date "Dec. 14, 1982". The project, which involved 'racetracks' and multiple shelters for each vehicle (the 'shell game', applied to nukes
), was eventually canceled due to high costs.
This is not to say there is no such tube system; only that it's not likely to have attained the site author's propositions. The hypothesis is basically sound, relying on tunnels bored in straight lines, that don't follow the Earth's curvature, to use Earth's gravity as part of the acceleration-deceleration system. This has appeared in Mechanics Illustrated, Popular Science, and a host of other magazines over the years. The last such proposal I recall included tubes built across the Atlantic and Pacific Oceans.