Background
Sibley was born in Walker County in east Texas to Horace McAdams and his wife, Nevada McAdams (1894–1969).
Sibley was born in Walker County in east Texas to Horace McAdams and his wife, Nevada McAdams (1894–1969).
She received her bachelor"s degree from Sam Houston State University in Huntsville, her master"s degree from the University of Houston, and a Doctor of Philosophy from Rice University in Houston.
She served as professor and chairman of the history department at Houston Baptist University and was briefly a visiting professor of history at the University of Texas at Austin. Among Sibley"s eight books are Travelers in Texas, 1761-1860 (1967), The Portuguese of Houston: A History (1968), Samuel H. Walker"s Account of the Mier Expeditions (1978), The Methodist Hospital in Houston: Serving the World (1990), and Lone Stars and State Gazettes: Texas Newspapers Before the Civil War (2000). She also penned several articles in the Journal of Southern History and Southwestern Historical Quarterly.
In 1974, she was named a fellow of the TSHA. J. Dale and Marilyn Sibley had three sons, David McAdams Sibley, an attorney-lobbyist who served in the Texas State Senate from 1991–2002 and as mayor of Waco from 1987–1988.
Doctor Stuart Dale Sibley of Dallas, and Doctor Mark McAdams Sibley of Richardson, Texas. She had two sisters, Dorothy McAdams Sparks, who predeceased her, and Ruth McAdams Ralston of Longview in Gregg County, Texas, the widow of Robert H. Ralston (1922–1991).
Services were held at the McAdams Chapel in Huntsville. Interment followed in McAdams Cemetery there.
In her later years, she was again a member of the same congregation. She was a member of the Daughters of the American Revolution, Daughters of the Republic of Texas, and the East Texas Historical Association.