The cache is not at the posted coordinates.
Did you know you are on the first transcontinental highway in America? This would be highway 6 and it is also called the Grand Army of the Republic Highway. This name is to honor the Union forces from the Civil War. There is some very interesting history about this highway and you’ll find that at this link, https://www.fhwa.dot.gov/infrastructure/us6.cfm .
For this mystery cache, here is the question, what is next? Given AIIACT, what letters come next? You can enter the 6 letters into the checker to get the final location.
Check your answer here.