30 years ago, two Harvard Business School professors had a plan. They wanted to change the world. Start filling the pipeline with female managers, they predicted, and in 10 or 20 years at most, those women would shift into senior positions. Once that took place, could an end to sexism in the workplace (and maybe everywhere else too) be far off? Anne Jardim and her partner, Margaret Hennig, wrote one of the first books of career advice for pigeonholed secretaries and ambitious assistants: The Managerial Woman. (View an interactive feature showing differences between men and women in corporate America.)

When it was published, in 1977, just 2.3 percent of the executives in U.S. firms were women. The book—a "groundbreaking" bestseller, according to the New York Times—was onto something big. Now, three decades later, 52 percent of all middle managers are women.

Poof! Sexism in corporate America—gone.

Twenty or 30 years ago, people thought it could actually work like that: Deal with sexism and be done with it. (View an interactive timeline of gender wars in America.) But sexism didn't end. Now we dread having to bring it up again. Why? Maybe because our failure stirs up fear and embarrassment at the idea that it will never go away. These thoughts are always with us but never more so than today, thanks to Senator Hillary Clinton's tumultuous presidential campaign. She was the "inevitable" Democratic candidate—until she wasn't. Once there was a charismatic male contender, we as a nation had to once again face our true feelings about gender and power. Suddenly the question is whether we are more gender-blind or color-blind.

Consider this: While women have made huge professional gains in the past three decades, progress now appears to have slowed or stalled. In some cases, it's even backsliding. Key indicators such as pay, board seats, and corporate-officer posts all reflect a leveling off or drop in recent years. Although the gap between men's and women's pay narrowed significantly through the 1980s, gains since then have been partly erased by a drop every few years. In 2006, women over the age of 25 earned 78.7 cents for every dollar earned by men, according to the most recent statistics from the U.S. Labor Department. That's a decline from 2005's figure of 79.4 cents on the dollar and also represents only about a 5-cent increase since 1991.

In the legal profession, the American Bar Association says the salaries of female lawyers are slipping in comparison with those of their male colleagues. Again according to the most recent statistics available, female attorneys' weekly wages amounted to 70.5 percent of male lawyers' in 2006, compared with 77.5 percent in 2005.

Among Fortune 500 firms, the number of female officers has declined each year since 2005, following substantial gains in the past decade. Sixty-four firms had zero female officers in 2006; last year the tally was 74, according to Catalyst, a nonprofit research and advisory organization that focuses on professional women. During the same period, the number of corporations with three or more female officers dropped from 234 to 203.

In the early and mid-1990s, the number of female appointees to Fortune 500 boards steadily increased. But since then, progress has slowed, and it stalled last year: In 2007, women held 14.8 percent of board seats in Fortune 500 companies. And some of the companies thought to be the coolest are the most shamelessly female-averse: Apple has one female board member, appointed just this year; Microsoft has one; and Google has two. A Microsoft spokesperson said, "We are proud of the makeup of our board of directors. Microsoft is sensitive to diversity and inclusion; it continues to be an ongoing area of focus across the company. Board membership will always be based on the qualifications and perspective that the people we're considering can bring to the company's business and shareholders."

Heidrick & Struggles is one of the world's top executive-search firms. Senior chairman and chief headhunter Gerry Roche groaned when I told him why I was calling. "There isn't sexism anymore," he said. "Or if there is, you can't rush things. Maybe it will take another generation to make things right."

He told me, "Boards are always asking me to bring them women candidates." But he still places nearly six times as many men as women. Of his top 10 recruiters, five are female. So why only one woman on his nine-person board? "That's a good question," he said.

Catalyst calculates that, at this rate, it will take 73 years for women to achieve parity with men at the board level. 2081, here we come!

The reasons behind the stagnation are tricky. Some people I spoke to suggested that, because of all the overt signs of progress—the Clinton candidacy, a woman speaker of the House, female Fortune 500 C.E.O.'s—the barriers women face today are more subtle and therefore harder to overcome. Basically, the popular perception is that women have made it, so there's nothing to discuss.

Therefore, if you're not a success, it's about you and your abilities (or lack of ability), because we can all certainly see that women have reached the top.

Mark Walsh, a venture capitalist and co-founder of Air America Radio, was surprised by these statistics. "I'm on two public boards and a ton of private boards, and the mantra is diversity. But as I think about it, when we interview females in the mix, the offer of a board seat typically goes to the nonwhite men—Latinos and African Americans. We think, Great, we've done diversity." He concludes, "Women have taken a backseat. They're not being allowed to drive in terms of corporate governance."