Martin Marietta Materials, Inc. is an American company and a member of the S&P 500 Index. The company is a supplier of aggregates and heavy building materials, with operations spanning 26 states, Canada and the Caribbean. In particular, Martin Marietta Materials supplies resources for the construction of roads, sidewalks and foundations. Martin Marietta's Magnesia Specialties business provides a full range of magnesium oxide, magnesium hydroxide and dolomitic lime products. The present-day materials business is distantly descended from Superior Stone, an aggregates company founded in 1939 in Raleigh, North Carolina. In 1959 the company was purchased by the American-Marietta Corporation, which merged with the Glenn L. Martin Company a year later to form Martin Marietta Corporation. Martin Marietta in turn merged with Lockheed Corporation in 1995, and a year later the "new" Martin Marietta was spun off as independent company, with Lockheed Martin retaining various aerospace, defense, and other manufacturing lines of business.
