Lamarck believed that the stretching elongated the giraffe's neck, which became a useful characteristic and was passed onto future generations. This resulted in the length of the giraffe's neck increasing over time. It is now commonly accepted that Lamarck's ideas were wrong.
The U.S. government openly stated that they would view any European interference in Latin America as "an act of aggression". This was articulated clearly in the Monroe Doctrine, which stated that the US would respond with military force.
Ah cool!
This would be referring to the Homestead Act! They would give the land to anyone who was willing to work on or improve the land.
The land was given almost free of cost and all the new owner of the land was required to do, was work the land until it was ready for farming/crops, and then they had to build a house for themselves (and possibly their family).
