John Steigauf at the International Association of Machinists and Aerospace Workers, where he's still fighting to protect the rights of employees.

John Steigauf was fighting a losing battle with type 2 diabetes. Diet, exercise, and medication: None of it was working, he felt exhausted all the time, and friends said he no longer looked like himself. Still, Steigauf put off what he really needed—insulin injections—for fear he would lose his job.

When Steigauf, then 47, finally went on insulin in 2004, his health improved but his fear proved well founded: He was deemed unfit to keep his position of 14 years with United Parcel Service. It was more than a decade after the passage of the Americans with Disabilities Act, landmark civil rights legislation that was supposed to protect Americans with disabilities, including those with chronic diseases, from workplace discrimination. But a string of Supreme Court decisions and lower court rulings had undermined the law's effectiveness, leaving Steigauf and others at the mercy of unsympathetic or uninformed employers.

A broad disability rights coalition, including advocates from the American Diabetes Association, knew only one strategy could restore what the courts had taken away: pushing a reform of the 1990 law through Congress and the White House to bring people with diabetes and other chronic medical conditions back under the legislation's umbrella. Last September, after years of advocates' lobbying, President George W. Bush signed the Americans with Disabilities Act Amendments Act, or ADAAA. The new law, which went into effect January 1, promises to bolster the rights of people with diabetes and many others for generations to come.