Answer:
Correct answer is negotiated a treaty with Spain for control of Florida.
Step-by-step explanation:
First option is not correct as the document Oregon Treaty was negotiated in 1846 by by Secretary of State James Buchanan.
Second option is not correct as Manifest destiny as a term emerged in 1845, long after Adams was secretary of State.
Third option is not historically accurate.
Last option is correct as this refers to Adams-Onís Treaty from 1819 that was signed when Adams was Secretary of State.