The first sizable american migration into texas occurred amid the following circumstances:
a. ongoing native american raids on mexican villages.
b. a new mexican nation in need of government revenue.
c. american westward expansion
d. all the above

D

Explanation: The history of Texas, as part of the United States, begins in 1845, but the occupation of the region dates from the Upper Paleolithic Period, around 10,000 BC.

option d is correct. corroborated sources of historical evidence   is necessary to validate a claim about an event in history.

historians tend to use written sources, but audio and visual materials as well as artifacts are important objects that supply information to modern historians.

historical sources are usually divided into two categories: primary and secondary sources. depending on the historian's intent, some sources shift their designation. determining what type of sources toimplement, and the level of credibility and reliability of those sources, is a significant step in critical thinking for the historian.

explanation:

thurgood marshall

explanation: in 1954, thurgood marshall and a team of naacp attorneys won brown v. board of education of topeka, kansas. in this landmark decision, the supreme court held that segregation in public education violated the equal protection clause of the fourteenth amendment.