Miller has worked as the union's chief of staff since 1999 and was previously the group's chief economist. Prior to that position, he served four years as senior analyst for agriculture and trade on the staff of the Senate budget committee.
Miller was also previously as vice president for government relations and then president of the National Association of Wheat Growers.
He was a co-chairman of the Canada-U.S. Joint Commission on Grains, a federal commission established to resolve grain trade issues between the two countries.
Agriculture secretary Tom Vilsack cited Miller's lifelong experience in supporting the president's nomination.
The National Farmers Union named a new president to the 250,000 member organization at their annual convention March 10. The group named North Dakota agriculture commissioner Roger Johnson.
Johnson recently served as president of the National Association of State Departments of Agriculture and participated in crafting the 2008 farm bill.
