Sentence:  Raymond Vernon reports that residents of East St. Louis have been driving across the Mississippi , through the heart of downtown <WSD>St.</WSD> Louis and out to the western suburbs for major shopping , simply because parking is easier at the big branches than it is in the heart of town . 
Meaning of the word marked with <WSD> tags:  the largest city in Missouri; a busy river port on the Mississippi River near its confluence with the Missouri River; was an important staging area for wagon trains westward in the 19th century