No line better summed up Winston Churchill’s eloquence than one delivered by President Kennedy, upon granting Churchill honorary American citizenship in 1963. “He mobilized the English language and sent it into battle,” said the President, quoting Edward Murrow.

Churchill’s granddaughter, the author Celia Sandys, quoted this on Friday, as she joined in celebrating the opening of the Morgan Library’s aptly titled exhibit, “Churchill: The Power of Words.” Her presentation was part of the Tina Santi Flaherty-Winston Churchill Literary Series, co-sponsored by the Writing Center at Hunter College and the Roosevelt House Public Policy Institute at Hunter College as well as in connection with the Churchill Archives Centre.

Ms. Sandys noted that after the attack on the World Trade Center, Churchill’s abilities were again in demand. “He stepped right out of the history books and back onto the international stage,” she said. Noted she: “It has been said that Hitler could persuade you that he could do anything but that Churchill could persuade you that you could do anything.” Churchill did this, she asserted, without the use of speechwriters.

She said that Churchill’s facility with words was helpful to his family: “Whenever he needed some money, he picked up his pen.” She went on to note how his children used to say, “We lived from pen to mouth.” The income helped support his lifestyle. Churchill, she said, once stated, “I am a man of simple taste, easily satisfied by the best.”

Ms. Sandys referred to the criticism Churchill faced for the disastrous Dardanelles campaign in World War I. But Ms. Sandys said, “When visionaries fail, they inevitably bounce back.” She said this defeat helped prepare Churchill for later war-time experiences.

The lighter side of Churchill came across in her lecture. Ms. Sandys said she was with her grandfather in 1959 in the Mediterranean on a yacht owned by Aristotle Onassis. The audience laughed when she said Onassis tried to go through the Dardanelles in the dead of night, so as possibly not to discomfort Churchill. “They thought I wouldn’t know where we were,” Churchill said the next morning, “but of course I did.”

Ms. Sandys told other anecdotes. She went on to say that while receiving honorary degree in Miami, Churchill reflected on his imperfect education, commenting, “No one has passed so few examinations and received so many degrees.”

The audience roared when Ms. Sandys related the following story once told to her at the White House: Churchill was once sitting around at a war-time conference taking some time off, when a drunk G.I. asked him, “Hey fatso, where’s the john?” Not missing a beat, the Prime Minister replied, “Turn left down the passage and there’s a door on the right marked ‘Gentlemen.’ But please don’t let that deter you.”

Ms. Sandys said Churchill’s wit was part of his armature. She said that when an opposing speaker in a parliamentary debate once observed that Churchill appeared to be dozing, the flummoxed speaker glowered at Churchill, asking, “Must you sleep when I’m speaking?” “No,” the British leader replied, “It is purely voluntary.”