Because they were thinly setteled and the Mexican government had long neglected them. List 3 details of the Treaty of Guadalupe Hidalgo.
Sources such as diaries though not very reliable can be used if there are a large amount of them showing the same date and event. Historical books written about the event especially those closer to the time would be able to help determine that the date is accurate as well.
He could post them on social media such as twitter and facebook. it would be better because so many people use social media outputs.
Government get its power from citizens voting.
