Smith Tower, located in Pioneer Square, is the oldest skyscraper in Seattle, Washington. Completed in 1914, the tower is named after its builder, firearm and typewriter magnate Lyman Cornelius Smith. Containing 38 floors, it was the tallest office building west of the Mississippi River until the Kansas City Power & Light Building was built in 1931. It remained the tallest building on the West Coast until the Space Needle overtook it in 1962. The building is a designated Seattle landmark.
Links: en.wikipedia.org, gizmodo.com