Northeast Corridor: The 363 miles of the 456-mile corridor connecting Washington, Philadelphia, New York and Boston, the busiest passenger line in the country, with trains regularly reaching speeds of 125 - 150 mph (201 - 241 kph).
OK..... that may be true.
My experience on Amtrack is that there is generally not able to exceed 60 or so.
On my trip back from Seattle to Syracuse last year it was 0 mph because they had cancellation after cancellation and I ended up flying