Gr0k说是西奥多罗斯福的时候开始的, 川帝快去掘墓：
Canada began supplying electricity to the United States in the early 20th century, with significant cross-border transmission starting around 1901. One of the earliest notable instances involved the Niagara Falls region, where hydroelectric power development was a joint effort between the two countries. On the Canadian side, the Ontario Power Company, established in 1887, started generating electricity at Niagara Falls, and by 1901, it was exporting power across the border to New York. This was facilitated by the completion of a transmission line from Niagara Falls, Ontario, to Buffalo, New York, marking the beginning of a formal electricity trade relationship.
In 1901, when Canada began supplying electricity to the United States, the President of the United States was Theodore Roosevelt. He assumed the presidency on September 14, 1901, following the assassination of President William McKinley. McKinley had been shot on September 6, 1901, and died eight days later, thrusting Roosevelt, his vice president, into office. So, while McKinley was president for most of 1901, including the early part of the year when the Niagara Falls transmission line opened, Roosevelt was in office by the end of that year and oversaw the period as this cross-border electricity trade began to take shape. Given the context of your question, Roosevelt is the most relevant answer as the president during the key moment of 1901 when this milestone was established.
当地时间3月10日，加拿大安大略省省长道格·福特宣布即日起对输美电力征收25%的关税，以回应美国总统特朗普对加拿大商品征收关税的措施。随后，特朗普在社交媒体发文质问“是谁允许外国向美国供电”，导致美国在关键能源领域被别人“卡脖子”？
可美国政府官网资料显示，美国部分区域长期依赖外部供电是基于《美墨加三国协议》（USMCA）条款所致，而签署这份协议的正是特朗普自己。
特朗普11日在“真实社交”平台发文质问：“为什么我们的国家会允许另一个国家为我们供电，即使是一小块地区？”他还表示，加拿大正在用影响美国人生活来作为与美国谈判的筹码和威胁。
然而根据美国政府官网留存的USMCA协议原文显示，在该协议 “能源及能源产品”这一章中，美墨加三国就电力自由交换进行了谈判，确定了能源产品零关税等条款。基于这一条款，加拿大的安大略省长期向美国明尼苏达州、纽约州和密歇根州供应电力。
特朗普与美墨领导人签署USMCA协议现场图。（路透社）
该协议由特朗普在2018年11月完成谈判，随后他和时任加拿大总理及墨西哥总统一同出席了协议签署仪式。根据美国国会官网的法案存档记录，该协议于 2020年1月被正式通过生效。
USMCA相关条款的截图（美国政府官网）
在注意到特朗普这一表态后，《每日野兽》等媒体和网民还找到了特朗普在2019年12月发布的一则网帖，他当时在网帖中盛赞USMCA，称“这将是美国有史以来达成的最好、最重要的贸易协议。”