Whenever there’s been a war for freedom, women have helped wage it.

They were on the battlefield in America’s struggle for independence and the fight to free the slaves. And, they were in the streets during the French Revolution.

That their efforts often were ridiculed, or ignored, explains why they’ve had to wage war for their equality, too.

Helping amplify their voices is “The Women’s History of the Modern World: How Radicals, Rebels, and Everywomen Revolutionized the Last 200 Years.”

It’s a tremendous job, and author Rosalind Miles rises to the challenge of the work’s scope.

Chronologically, she begins with America’s Revolutionary War and Deborah Sampson. At 21, Sampson cut her hair, put on men’s clothes and enlisted in the Fourth Massachusetts Regiment as Robert Shirtliff, where she led reconnaissance missions and fought on the battlefield.

Shot in the groin during one skirmish, Sampson kept fighting. When she had a moment, she extracted the musket ball with a penknife and stitched up the wound. Although an Army doctor eventually discovered her ruse, Sampson continued serving until her honorable discharge in 1783.

America’s War of Independence would soon inspire French revolutionaries, with women joining in the shouts of “Liberty, Equality, Fraternity!”

On Oct. 5, 1789, a furious crowd of Parisian women, including clerks, courtesans, and wives marched to the Palace of Versailles. They trudged 17 miles in the rain. When they returned to the city the next day, it was with the terrified royal family in tow.

“Women were in the forward ranks of our revolution,” wrote historian Francois Mignet. “We should not be surprised at this, they suffered more.”

The monarchy was toppled, and a republic established. The image of the mythical Marianne — a brave, beautiful warrior — became a symbol of the new nation.

However, it was men who were in charge.

The feminist Olympe de Gouges dared say it, too, publishing “The Rights of Woman and of the Female Citizen” in 1791. The Revolution had failed one-half the country’s citizens, she observed.

“Women, wake up … recognize your rights!” she implored. “Oh women, women, when will you cease to be blind?”

The men running the country were certainly watching, and they recognized a threat. They charged de Gouges with “attacking the Republic.” Her punishment? The guillotine.

Meanwhile, in the United States, women had won some rights, although it was chiefly the right to work themselves to death. They filled many of the mills the Industrial Revolution created. Some employees were as young as 3. Women’s wages were, at best, two-thirds of a man’s.

Female soldiers were soon serving in another war, too, this time a civil one. Frances Clalin Clayton, a mother of three, enlisted in the Union Army alongside her husband. When he fell in battle, she stepped over him and kept fighting.

But obtaining true equality — the right to vote, the right to control their bodies, equal pay for equal work — would prove harder to win.

The first women’s rights convention in the world was held in July 1848, in Seneca Falls, N.Y. Three hundred men and women attended. At its conclusion, 100 signed the Declaration of Rights and Sentiments, a call for equality that leader Elizabeth Cady Stanton based on America’s Declaration of Independence.

Although Sojourner Truth was a fiery speaker, the feminist movement was dominated by white women like Stanton and Susan B. Anthony. Together, they pushed the equality agenda forward, with its central insistence on the right to vote.

They made an unbeatable team, with Stanton planning their strategy and Anthony giving the speeches.

Stanton remembered their sisterhood as: “I forged the thunderbolts. She fired them.”

Even if an official war wasn’t recognized, women were very much waging one here and around the world. And, like all wars, there were casualties. Cops beat suffragists and hauled them off to jail. Prisoners launched hunger strikes and were force-fed.

In 1913, Emily Wilding Davison, a British activist was trampled to death at a horse race. It was a horrific accident; she was trying to attach a banner for women’s voting rights to a galloping horse. Many saw it as a martyrdom.

“She died for women,” announced The Suffragist.

Seven years later, American women won the vote. Yet, a century later, the battle for reproductive rights continues.

Pregnancy always has posed a lethal risk for women. Yet in 1873, the U.S. Congress categorized birth control devices as “Articles of Immoral Use” and made distributing them a federal crime. Even basic sex education was banned as obscene.

Five years later, the elderly Ann Trow — who had provided abortions for more than 40 years — was caught selling contraceptive pills to a New York undercover cop. Facing a lengthy prison sentence, she climbed into a bath and slit her throat.

“No woman can call herself free who does not own and control her own body,” said family planning advocate Margaret Sanger. “It is the first step she must take to be man’s equal.”

Sanger opened her first birth control clinic in Brownsville, Brooklyn, in 1916, dispensing diaphragms smuggled in from Canada. It was immediately shuttered. Sanger spent a month in jail. Once released, she returned to work.

Finally, in 1918, Sanger won a small but crucial victory: A judge ruled that doctors could discuss birth control with patients, as long as it was for “medical reasons.” Although Sanger’s writings grew increasingly controversial — she was anti-abortion and pro-eugenics — she promoted family planning until she died in 1966.

By then, it was a different world.

In 1949, France’s Simone de Beauvoir published “The Second Sex,” insisting that society saw men as the norm and women as the other. The Vatican banned the book, but once it was translated into English four years later, it inspired a new generation of American feminists.

One was Betty Friedan. A student at Berkeley, she turned down a Ph.D. fellowship at the insistence of her then-boyfriend. She eventually married and started a family. But she couldn’t ignore the gender inequality she saw around her.

In 1963, she published “The Feminist Mystique,” asserting: “Man is not the enemy here, but a fellow victim. The real enemy is women’s denigration of themselves.” Friedan later co-founded the National Organization of Women.

The modern women’s movement continues to grow. Elected officials like Shirley Chisholm and Alexandria Ocasio-Cortez, activists and authors like Gloria Steinem and Germaine Greer, and lesser-known women have shattered ceilings in most industries. Yet, there is so far to go.

“The women’s revolution is the greatest piece of unfinished business in the history of the world,” Miles writes. “It must be a revolution, because we are calling for a full turn of the wheel, not just the slow erosion of women’s supposed inferiority which has already taken hundreds of years. As the nineteenth-century suffragists found, rational argument about female subjugation, appealing to ideas of justice to right this huge and ancient wrong, did not give the women the vote or bring equality. A revolution for women is therefore necessary and overdue. Women have tried everything else, including patience.”

Jacqueline Cutler writes for the New York Daily News.