Currently, the United States is one of the VERY FEW countries in the world that still uses the metric system.
The majority of the world converted to the metric system in the 19th century, however, the United States refused to convert. With most of the world using the metric system, this creates numerous problems with importing/exporting, foreign development, education, foreign transportation, and quite frankly it's just confusing.
When traveling to somewhere remotely close to the United States, such as Canada & Mexico, tourists are tasked with converting temperatures, speed limits, and other pivotal measurements during their stay. Why should the United States continue to be one of the only three countries on Earth that still continually refuse to convert to the metric system?