That is not to say he was alone, though.
Hovering over his shoulder was Brian O’Connor, the longtime chief of staff to his dad, Joseph P. Kennedy II. And choreographing the first-time candidate’s day of five stops was Tom Keady, who has done advance work for numerous Kennedy campaigns.
Thus the balancing act begins as a third generation of Massachusetts Kennedys enters the political fray.
There is pride in the name, as Joseph Kennedy III acknowledged to reporters. There also is an obvious campaign benefit, as will be apparent next week during a series of fund-raisers in Washington - including on Wednesday, which marks what would have been the late senator Edward M. Kennedy’s 80th birthday.
But Joseph Kennedy has seemed determined to strike out on his own, building off the advantages offered by his famous name but driven to seal his future himself.
He has employed the knowledge he accumulated at Stanford University and Harvard Law School in the Peace Corps, at a legal aid service, and as an assistant district attorney.
Now, at 31, he is asking voters to let him join the family business. He is running in the Fourth Congressional District, currently served by US Representative Barney Frank, a fellow Democrat, who is retiring.
“I am going to go, over the course of the days and weeks ahead, to knock on more doors, make more phone calls, stand out, walk in more parades, do whatever I need to do, to earn their respect, their trust, and, hopefully, their support,’’ Kennedy told reporters.
Should he win his party’s nomination, there is the potential for a spirited contest.
Brookline School Committee member Elizabeth Childs - a graduate of Mount Holyoke College, the University of Cincinnati College of Medicine, and a psychiatrist who served in the Romney administration - is one candidate for the Republican nomination.
Sean Bielat is another.
Like Childs, the former Marine has a resume that matches the luster of Kennedy’s: Georgetown University, MBA from Penn’s Wharton School, and a master’s degree in public policy from Harvard.
