total: 240,000 km mainline routes (nongovernment owned), standard gauge (1.435 m) (1989)
See also Transportation in the United States.
... 2nd century - 3rd century - 4th century Decades: 190s 200s 210s 220s 230s - 240s - 250s 260s 270s 280s 290s Years: 237 238 239 240 241 - 242 - 243 244 245 ...