Answer: 1. The United States annexes Hawaii in 1900 - Imperialism
2. The United States declines to give aid to Hungarian patriots in 1849 - isolationism
3. The United States proposes the Open Door Policy in 1899 - intervention
4. The United States annexes Samoa in 1899 - imperialism
5. The United States attempts to mediate in the Venezuela-Great Britain dispute in 1895 - intervention
Explanation: Imperialism is a policy of extending a country's power and influence through colonization, use of military force, or other means.
Isolationism is the policy of remaining apart from the affairs or interests of other groups, especially the political affairs of other countries.
Intervention is forcible or dictatorial interference of one country or sovereign state in the internal or external affairs of another.