Instructions: In this task, you will be given a passage to read. A fill in the blank question will be given to you.  Your answer should fit the blank appropriately.
Input:  The arsenal was constructed at the request of Governor James Sevier Conway in response to the perceived dangers of frontier life and fears of the many Native Americans who were passing through the state on their way to the newly established Oklahoma Territory . Thirty @-@ six acres were appropriated on the outskirts of Little Rock by Major Robert B. Lee of the U.S. Army . The land had been previously used as a racetrack by the local jockey club . John Wormley Walker , a builder for the Federal Government , supervised the construction . Originally $ 14 @,@ 000 was allocated for the construction of the arsenal , but proved inadequate . The budget was later increased to $ 30 @,@ 000 . Work began on the Tower Building in 1840 , and it was the first permanent structure of the arsenal to be built . Being originally constructed to store ammunition , the building was designed with 3 @-@ foot @-@ thick ( 0 @.@ 91 m ) exterior walls . The original plans called for it to be built of stone , however , masonry was used instead . The Arkansas Gazette referred to the structure as fill in the blank  :The arsenal was constructed at the request of Governor James Sevier Conway in response to the perceived dangers of __________________ life and fears of the many Native Americans who were passing through the state on their way to the newly established Oklahoma Territory . 
Output:
 frontier 