Should shortened generic forms of proper nouns be capitalized?

In general, lowercase generic forms of proper nouns:

the United States Army, the army

President Kennedy, the president

the Brooklyn Bridge, the bridge

Housatonic River, the river

But, as The Chicago Manual of Style notes, capitalize generic terms if necessary for clarity (“Wars”):

the French Revolution, the Revolution of 1789, the Revolution, the revolution of 1848

Work Cited

“Wars and Revolutions.” The Chicago Manual of Style, 17th ed., sec. 8.113, U of Chicago P, 2017, www.chicagomanualofstyle.org/book/ed17/part2/
ch08/psec113.html.