Peyton Randolph is the "Mr. President" Henry addresses in his speech…and he was quite used to being called that and to being treated with respect in general, thank you very much.
Peyton Randolph was born kind of a big deal. As a member of the wealthy and influential Randolph family, he grew up tight with King (George II) and Country (Great Britain). Randolph's dad (that's Sir John to you) was the King's attorney (think State's attorney, i.e., the Prosecution) for Virginia, and his grandpa (Colonel William Randolph) had been a major player in Virginia since he immigrated in 1674. (Source)
Did we say "kind of a big deal"? We meant "big deal." Full stop.
Our boy Peyton grew up rich in Williamsburg, then the capital of Virginia, had private tutors, and studied law in London before graduation from the College of William and Mary in 1742. In 1745 or 1746, he married Elizabeth Harrison and was admitted to the Virginia bar as a practicing attorney around the same time.
Three years later, he took over his dad's job as King's attorney for Virginia, and he remained in that position for eighteen years. That same year, he took his seat in the Virginia House of Burgesses for the first time, where he opposed taxes on land purchases.
Being King's attorney was a pretty sweet (and lucrative) deal, so what prompted Randolph to resign in 1766?
Well, he and the Crown had been having issues for a while. In 1754, he campaigned in London against new taxes. He got some of the taxes revoked, which made an enemy of Robert Dinwiddie (which we think is maybe the cutest name ever) then the Royal Governor of Virginia. This little move gained him a pro-colonial rep.
The Stamp Act (check out the "Timeline" for more on that) ultimately led to his resignation as King's attorney. This move made him even more popular in the House of Burgesses than he already was. He was elected Speaker, a post he held until his death in 1775—which is how he automatically became president of the Second Virginia Convention.
While Randolph was always a political moderate, he was very much opposed to the actions of the Crown between 1765 and 1775, and this put him in the same camp as more radical American patriots like Patrick Henry and Thomas Jefferson. The other Founding Fathers valued his calm personality and his mad legal knowledge.
In 1774, Randolph called on Virginians to engage in economic resistance to Great Britain (i.e. a boycott of goods). Great Britain was not thrilled with this, and gave him a big wag of the finger.
He was then elected to the First Continental Congress, which went on to elect him as its president. After the First Continental Congress ultimately decided to support Boston in opposing the Crown's actions there, Randolph returned home to see what was up and called the Second Virginia Convention, which became famous as the scene of Henry's "Give Me Liberty or Give Me Death" speech.
Randolph was elected to attend the Second Continental Congress in Philadelphia and was elected president again, but he died from "apoplexy" (probably a stroke) while there. His body was transported from Philadelphia to Williamsburg to be buried at William and Mary, which shows how much respect Virginians had for the dude.
Moving a body across state lines was as big a deal then as it is now, we guess.