William M. Rickman Sr., 84, a businessman who developed much of the Interstate 270 corridor and owned racetracks and a quarry, died Sept. 20 at Shady Grove Adventist Hospital in Rockville. He had a respiratory ailment.

Mr. Rickman, a Potomac resident, started Capitol Machinery and Tool in the 1950s.

He later formed W.M. Rickman Construction Co. and was involved in operations until recently.

Starting in the 1970s, he began rapid development of the I-270 corridor around Rockville, including the Shady Grove Life Sciences Center that houses biotech businesses.

As his interest grew in thoroughbred race horses -- he owned many -- he became the owner of the once-defunct Delaware Park near Wilmington, Del., and Ocean Downs racetrack on Maryland's Eastern Shore.

In 1997, he donated his 100-acre horse farm in Boyds to the Maryland-National Capital Park and Planning Commission.

William Monroe Rickman Sr. was born in St. Charles, Va., and raised in Sylva, N.C. He was in the Civilian Conservation Corps before Army service as a machinist in Italy during World War II.

His holdings over the years included Stoneyhurst Quarry in Potomac.

His marriage to Zoe Gaudin Rickman ended in divorce.

Survivors include five children, Cynthia Rickman of Virginia Beach, Lynn Green of Towson and Sheila Kessinger, William M. Rickman Jr. and Zoe Roa, all of Potomac; two sisters, Ruth Owens of Laytonsville and Esta Cantrall of Brevard, N.C.; and 10 grandchildren.

William Rickman enjoyed horses and racing.