instruction: In which country did the M&NA railroad exist.
context: The Missouri and North Arkansas (reporting mark M&NA) was a railroad in Missouri and Arkansas from 1906 to 1946.
  
  The railroad began as the Eureka Springs Railway in 1883 as a line from the St. Louis–San Francisco Railway in Seligman, MO, reaching the resort town of Eureka Springs, AR in 1883.
response: The M&NA was a railroad in Missouri and Arkansas, which made it part of the United States.