CEDAR RAPIDS — Often serving as an emissary telling the community’s story to local and national audiences, the area’s foremost historian — nicknamed “Mr. History” — is resigning later this month from The History Center, the organization’s executive director said Tuesday.Mark Stoffer Hunter submitted a letter of resignation last week saying his final day at the center is April 30, Executive Director Jason Wright said.Stoffer Hunter was hired in 2000 and has worked for the organization off and on in various capacities ever since.“We wish him all the best,” Wright said.