On the other hand....
"Unification to standard gauge on May 31 – June 1, 1886 [United States]
In 1886, the southern railroads agreed to coordinate changing gauge on all their tracks. After considerable debate and planning, most of the southern rail network was converted from 5 ft (1,524 mm) gauge to 4 ft 9 in (1,448 mm) gauge, then the standard of the Pennsylvania Railroad, over two days beginning on Monday, May 31, 1886. Over a period of 36 hours, tens of thousands of workers pulled the spikes from the west rail of all the broad gauge lines in the South, moved them 3 in (76 mm) east and spiked them back in place.[6] The new gauge was close enough that standard gauge equipment could run on it without problem. By June 1886, all major railroads in North America, an estimated 11,500 miles (18,500 km), were using approximately the same gauge. To facilitate the change, the inside spikes had been hammered into place at the new gauge in advance of the change. Rolling stock was altered to fit the new gauge at shops and rendezvous points throughout the South. The final conversion to true standard gauge took place gradually as part of routine track maintenance.[6] Now, the only broad-gauge rail tracks in the United States are on some city transit systems."
https://en.wikipedia.org/wiki/Track_gauge_in_the_United_Stat...