Why did so many nations want to find the northwest passage?

Many nations wanted to find the U. S passage, because they wanted to find a quicker route to Asia. They thought going around Africa was way too long and going across the Mediterranean Sea was too expensive and risky. They thought that sailing west would get them to Asia in no time. In reality, it was North America and they would have to go much farther in order to get to Asia, but they did not know that back then.