Seven years ago, at the beginning of the city's third century, the mayor of Detroit, Michigan, pried open a box that had been sealed for 100 years. Inside was a stack of yellowing letters that are now safely stored in a Detroit museum.

As the nation marks National Women's History Month this March, we're reminded of some prophetic insights contained in one of those letters. It was written by Sara Skinner, about whom little is known today.

"There is no greater evidence of the progress of an era than that found in the progress of its women," Ms. Skinner wrote in 1900. "One hundred years ago," she went on, "married women could not control their property or will it away at death. . . . The husband collected and used her wages. He could legally whip her if he wished. Very few occupations were open to women. No college admitted them. Men did most of women's thinking -- or thought they did and must -- because women's minds were so inferior.

"But," Ms. Skinner continued, "women were thinking, and there were premonitions of coming events."

One of these events, at long last in 1920, was gaining the right to vote, anywhere in America, just as Sara Skinner foretold it. "Ignorance, bigotry, conservatism, prejudice, and fear concerning women's use of the ballot will have passed away," she wrote.

Today, American women are free to do just about everything they were discouraged from doing, or forbidden to do, in 1900. They can even make a quite-serious run for president. Of course, women also have more opportunities to fail as well, and to stress out and endure scrutiny and criticism. But we suspect Sara Skinner would have been OK with that.