States being able to issue their own paper money would lead to problems such as counterfeiting and people not being able to use money from a certain state in a different state.
The rigjts of repuptaion of other national security public order public heath and morals
The Kecksburg UFO incident occurred on December 9, 1965, at Kecksburg, Pennsylvania, United States in North America, when a fireball was reported by citizens of six U.S. states and Canada over Detroit, Michigan and Windsor, Canada
it´s not from google btw, I searched on bing