Her visit to America took place 165 years ago; this was in Champion, WI.
The Church approved this apparition in 2009; there is an annual pilgrimage that takes place on the first Saturday in the month of May.
More information can be found here: WalktoMary.com
Not Vatican approved.
From the time they were first founded and named, the Americas consist of North, Central, and South America. It is more accurate to say that her appearance in WI was her first visit to the United States of America.