U.S. Route 99, also known as the "Pacific Highway," was a major north-south highway in the western United States. It ran from the Mexican border in California to the Canadian border in Washington, covering approximately 1,500 miles. The route connected several key cities, including Los Angeles, San Francisco, and Seattle, and played a significant role in the development of the region's economy and tourism. Established in 1926, U.S. Route 99 was part of the original U.S. highway system. Over the years, it underwent various changes and improvements, eventually being replaced by the Interstate Highway System. Today, many segments of the original route are still in use as state highways or local roads.