The Following Questions Refer to the Excerpt Below

The following questions refer to the excerpt below.
"And yet again,in his message of December 7,1847,that "the Mexican Government refused even to hear the terms of adjustment which he [our minister of peace] was authorized to propose,and finally,under wholly unjustifiable pretexts,involved the two countries in war,by invading the territory of the State of Texas,striking the first blow,and shedding the blood of our citizens on our own soil."  And whereas this House is desirous to obtain a full knowledge of all the facts which go to establish whether the particular spot on which the blood of our citizens was so shed was or was not at that time our own soil:"
Abraham Lincoln,1848
-The spot Lincoln is referring to in the above excerpt was

A) Ft. Sumter, where the Civil War began.
B) where fighting between Mexican and United States forces occurred on the Rio Grande boundary.
C) the Alamo, where the Texans fought for their independence from Mexico.
D) the site where American forces invaded Canada.