Answer:
1. William WALKER
2. Clayton-BULWER Treaty
3. Perry
4. Japan
5. Cuba
6. Ostend
Explanation:
According to the historical records, Expansionists, especially in the South, had a field day in the early 1850s. Note the adventures of William WALKER in Nicaragua and the resolution of disputes with Britain over a potential canal route across the Isthmus of Panama in the Clayton-BULWER Treaty of 1850. A fleet under Commodore Matthew PERRY helped open JAPAN to trade ties in 1854. And plans to grab CUBA from Spain were foiled when the OSTEND Manifesto became public in 1854.