The USA and Canada are two powerhouses sharing the longest border at 5525 miles. At one point in history, Canada was a part of the oh-so-great British Empire, which meant the USA and Britain would negotiate their boundaries again. They established the Oregon Treaty, which extended the border along the 49th parallel until the Strait of Georgia. This agreement would soon cause many major and minor problems because setting a line off parallel lines always contains disputes.
Point Roberts is an exclave of Washington state, famously caused by the Oregon Treaty. Although the two countries altered the border to ensure Vancouver Island would stay Canadian, Point Roberts slipped through the cracks. This issue went unnoticed until after the Treaty was signed, and the two countries never bothered to make the change. Point Roberts has an area of about five thousand square miles and a population of around one thousand Americans. It is a 25-mile drive to the rest of Washington and is a daily commute for some residents of the small exclave.
Another comparable situation arose in Northwest Angle, Minnesota. Similarly to its twin brother, Point Roberts, the Northwest Angle was an effect of the 49th parallel. Before the countries came to terms with the border, there were no maps of the area west of Lake Superior. The boundary was stretched and placed at the Northwestern most point of The Lake of the Woods. The officials at the time thought that the lake was comparatively more circular and closer to the 49th parallel than it was in reality. As a result of this false understanding, the border went far up to meet the Northwestern most point of the lake and then back down to join the 49th parallel, and the Northwest Angle was born. The island is much bigger than its counterpart at 116 square miles and contains a minuscule population of around 150 residents. Interestingly, the Angle inhabits precisely one citizen who identifies as Native American, while the other 99.2% identify as White.
Accommodating this wacky border includes several airport runways intersecting through it. During the early years of World War 2, the United States wanted to stay neutral but also wanted to provide aid to the allies such as Britain and France. A neutrality policy was established, which allowed the United States’s sale of military equipment to friends in Europe, but it came with conditions. One requirement is that the customer country must transport their equipment. Canada had previously declared war on Germany, and as a result, planes took off from Canada. The US still needed to get the aircraft over the border into Canada, so they were wheeled between two neighboring airports, Sweetgrass Airport and Coutts Airport. The operation was successful, leading to several new, border-intersecting airports.