The major US acquisitions of land from Mexico during the mid-1800s were the annexation of Texas, the Louisiana Purchase, and the Adams-Onís Treaty.
the Louisiana Purchase, the Adams-Onís Treaty, and the Gadsden Purchase.
the Louisiana Purchase, the Mexican Cession, and the Gadsden Purchase.
the annexation of Texas, the Mexican Cession, and the Gadsden Purchase.

What effect did john hay’s open door policy letters have on the imperial powers of britain, france, germany, russia, and japan? a. it provoked the imperial powers to declare war on the united states. b. it caused the imperial powers to restrict trade in their trade with china. c. it warned the imperial powers that the united states would soon declare war on china. d. it signaled to those powers that the united states would take a larger role in world affairs than before.