PHILADELPHIA, July 27 — Meryl Streep, the most accomplished, awarded and chameleonic actress of her generation, once confessed something approaching envy for Hillary Clinton: For women of her age, Streep said, Clinton was the yardstick by which they inevitably measured their lives — sometimes flatteringly, sometimes not.

Last night, Streep took to the floor of the Democratic National Convention here to make the case that Clinton, the object of that admiration, worry and judgment, was the right choice for the presidency.

"What does it take to be the first female anything?” Streep asked. "It takes grit and it takes grace.”

In her speech shortly after 11pm Eastern time, Streep, 67, placed Clinton, who is 68, in the pantheon of pioneering American women, from Amelia Earhart and Harriet Tubman to Sandra Day O’Connor and Geraldine Ferraro.

She dwelled the longest on Deborah Sampson, a woman who disguised herself as a man to serve in the Continental Army.

Sampson was shot while serving and removed the musket ball herself to avoid revealing her gender.

The message was not lost on the room — and Streep made sure of it: "Hillary Clinton,” she said, "has taken some fire over 40 years.”

For Streep, as beloved and inoffensive an actor as there is in Hollywood, the convention was a political coming-out of sorts, in which she publicly endorsed a candidate during a partisan celebration.

But neither her activism nor her embrace of Clinton was new.

Like Clinton, she grew up in a middle-class household, attended a women’s college, dabbled in campus protests and went to graduate school at Yale.

(Clinton received a law degree in 1973; Streep received a master’s from the School of Drama in 1975.)

Both, she said in a 2012 speech, had called their mothers from college — collect — insecure about their merit and chances for success.

"And both of our mothers said, ‘Don’t be ridiculous. You’re not a quitter,'” Streep said at the time.

Streep’s political consciousness, forged in the era of the Vietnam War and second-wave feminism, has turned her into one of Hollywood’s most outspoken advocates of equal pay and rights for women, on screen and off.

Last summer, Streep personally lobbied members of Congress to revive and adopt the Equal Rights Amendment, which would make discrimination against women unconstitutional.

Streep sent each member a letter urging them to "stand up for equality — for your mother, your daughter, your sister, your wife or yourself”.

Congress is not expected to act on the measure.

Streep’s reverence for the Democratic nominee has not blinded her to the shortcomings of the Clintons. In her campaign to change how Hollywood — and the broader American culture — treats women, she has ruefully recalled how many men of her generation have told her that their favourite performance was her turn as Linda, the docile checkout girl from The Deer Hunter, according to a new biography, Her Again: Becoming Meryl Streep, by Michael Schulman.

One of those men, Schulman wrote, was Bill Clinton.

Yesterday, Streep took the stage right after Bill Clinton had finished speaking, predicting the country would soon elect its first female president.

"She will be the first,” Streep said, "but she won’t be the last.” — The New York Times