On June 4, 100 years ago, the U.S. Senate passed the 19th Amendment to the United States Constitution, ensuring that Americans cannot be denied the right to vote on the basis of sex. From there, the amendment was debated and contested nationally. It became law on August 18, 1920, after being ratified by two-thirds of the states.

The amendment marked the culmination of decades of activism by leaders of the women’s suffrage movement, which laid the groundwork for future protests on behalf of women’s liberation. With help from photographs from the archives of The Boston Globe, which are housed at Northeastern, we took a look at key events that led to—and resulted from—the fight for equal rights for women.