Because at that time, The pathway to Lusittiana was a territory conquered by the Germans troop during their conflict with Great Britain in World War I.
The Germans give the warning following the international law of warfare at that time that indicates each nations should give warning to normal civilians if they intended to target a certain area.
B, it was when the western pioneers moved east to discover new land to grow crops and make population XD
When Mexico achieved its independence from Spain in 1821, New Mexico became a province of Mexico, and trade was opened with the United States. ... Two years later, the Treaty of Guadalupe Hidalgo ceded New Mexico to the United States, and in 1853 the territory was expanded to its present size through the Gadsden Purchase.