To keep information a secret, So they tell limited amount of people.
The fourth of July is the day of freedom for the people of America. In the speech, Douglas comments on the celebration of the day and says that to celebrate such a day is very ironical. He says that the celebration of freedom which the people are celebrating is in reality still under slavery. Hopefully this helps :)
I think 1492. but i could be wrong.
Vasco da Gama. Vasco da Gama was the first European to open a sea-based trade route to India. In an epic voyage, he sailed around Africa's Cape of Good Hope and succeeded in breaking the monopoly of Arab and Venetian spice traders.
