A century and a half ago back during John Wesley Powell's time when he correctly identified the 100th Meridian as the approximate boundary, the line has steadily shifted eastwards to around the 98th Meridian today.

一个半世纪前，当约翰·韦斯利·鲍威尔正确地将子午线 100 度确定为近似边界时，这条线已经稳步向东移动到今天的子午线 98 度左右。