Linda, you might check the book, Arkansas Odyssey: The Saga of Arkansas from Prehistoric Times to Present, by Dr. Michael Dougan. He might have “contemporary” sources listed that could help with your quest. The follow is an excerpt:

The Memphis and Little Rock line made the most progress. Memphis voted $350,000 in bonds to start the work, and more than 400 Irish laborers laid tracks form Hope field to the St. Francis River at Madison. The first locomotive in Arkansas, the Little Rock, made its maiden run in 1857, but Mississippi River floods that year damaged the line heavily. At the other end, construction started at Huntersville (North Little Rock) but ended during the Panic of 1857. The Civil War spurred new work, and finally, in January 1862, William E. woodruff drove the last spike on the section linking Little Rock to DeValls Bluff. The middle section between the White River and the St. Francs River through the Cache River bottoms was not completed until 1869.

That failing, you might consider contacting Dr. Dougan. He is in the History Department at Arkansas State University in Jonesboro.