Long established in Sedalia, he is presently owner and manager of National Valuation Services, Inc., in Sedalia, Springfield and Independence, MO and Mathewson Broadcasting KDRO. He has long assumed an active participative role in community and area activities and is an avid sportsman.

Honors: "Friend of Education Award" from Missouri School Boards Association; Honorary Doctorate of Education Degree from Missouri Western State College; 1991 Hallmark Missouri Public Service Award; Statesman of the Year, News Tribune Co.; Honorary Doctor of Humanities Degree, Missouri Valley College; James C. Kirkpatrick Excellence in Governance Award; Missouri Community College Association's Distinguished Legislator Award; University of Missouri System Presidential Citation; to name a few.

First elected to serve in the Missouri House of Representatives in 1974, he was re-elected to the House twice. Elected to the Missouri Senate in 1980, Senator Mathewson is presently serving his fourth term as Senator of the 21st District that includes Pettis, Saline, Chariton, Lafayette, Ray and Caldwell Counties and part of Jackson County. In November, 1984, and in 1986, Senator Mathewson was elected Majority Floor Leader of the Senate. In January, 1989, he was unanimously elected by his peers to serve as President Pro Tem of the Missouri Senate, and re-elected in January, 1991, 1993 and 1995.

He serves as Chairman of the Local Government and Economic Development Committee, and also serves on the following committees: Commerce and Environment, Financial and Governmental Organization, Gubernatorial Appointments, Insurance, Labor and Industrial Relations and Rules, Joint Rules and Resolutions.