<human>:  Why did the US build the Panama Canals?
<bot>: The Panama Canal was built to allow ships to bypass the long route around the tip of South America. The canal is about 14 miles long and is only 1.25 miles wide at the narrowest point. The canal was built by the US between 1904 and 1914, and it cost $400 million dollars to build. The canal is still in use today, and it is a vital part of US trade and commerce.