What is the Canada–United States border traditionally called?
- The 49th Parallel Fortress
- The Great Wall of the North
- The Iron Curtain
- The world’s longest undefended border
Answer: The world’s longest undefended border
The Canada–U.S. border is traditionally called “the world’s longest undefended border.” Millions of Canadians and Americans cross it safely every year. The Peace Arch at Blaine, Washington, symbolizes the close ties and common interests of the two countries.
Learn more: Canada and the United States
- The United States is Canada’s largest international trading partner, and each country is the other’s largest trading partner.
- About 72% of Canadian exports went to the United States in 2025.
- Canada and the U.S. have the biggest bilateral trading relationship in the world.
- Integrated Canada–U.S. supply chains compete with the rest of the world.
- Canada exports billions of dollars worth of energy products, industrial goods, machinery, equipment, automotive, agricultural, fishing and forestry products, and consumer goods.
- The border is traditionally called “the world’s longest undefended border.”
- The Peace Arch at Blaine, Washington, inscribed “children of a common mother” and “brethren dwelling together in unity,” symbolizes the two countries’ close ties and common interests.