Try using method cornell notes,use highlighters,make it simple or any other way that might help you understand your notes.
Listen carefully to them and ask for help if you need to.
Primary sources told an account of what actually happened because they were recorded from the actual event itself/saw the actual event
secondary sources (like our textbooks) arent 100% accurate because they are based off of the primary sources
Answer:
The Mexican army attacked them. The main cause of the war was the westward expansion of the United States. All through the 19th century Americans believed it was their right to expand westward. At the time they believed they could conquer the people already living on the land and take it for the United States.
Explanation: