Billington, Ray Allen. <br/><br/>
Westward expansion :  a history of the American frontier / 
by Ray Allen Billington, Martin Ridge. 
 - 5th ed. 
 - New York, N.Y. :  MacMillan,  1982. 
 - xv, 892 p., maps. 
<br/><br/> Includes bibliography and index. 
<br/><br/><label>ISBN: </label>0023098600 
<br/><br/><label>Subjects--Topical Terms: </label><br/>United States--Territorial expansion.<br/>United States--History.<br/>Mississippi Valley--History--1803-1865.<br/>West (U.S.)--History.