Answer:
The author supports his opinion about Washington's views of people's freedom and identity by stating that the unity and oneness of people can result to remarkable achievement.
Textual evidence to support this:
"...not the old idea that we are better apart, but the high hope that people from the four corners of the earth could do remarkable things together, even build a nation, and show humanity that we are better together."
Step-by-step explanation:
From this excerpt, it's seen that Washington is calling and advocating for unity, togetherness and oneness among people in order to achieve remarkable results. He believes in respect, relationship and service for the common good.