Final answer:
The formality of the address to William Henry was due to the historical context and traditional standards of oratory, which required speakers to use a serious and respectful tone in their public communications.
Step-by-step explanation:
The address to William Henry was formal because of the context and tradition of oratory of the time. Formality in speeches, especially those of significance and public address, was the norm in historical contexts, reflecting the manners and standards of communication of the period.
Prominent figures like President Washington and public speakers such as Frederick Douglass, Booker T. Washington, and Abraham Lincoln tailored their addresses to fit a formal, respectful, and impactful tone. This practice aimed to convey ideas effectively while maintaining a sense of decorum and respect towards the audience and topic, as evidenced in the significant speeches of the time.