“I’m optimistic that in not too long the U.S. will join the rest of the world,” said Vicki Shabo, vice president of the National Partnership for Women and Families. “We are the only high-wealth developed country that doesn’t guarantee paid paternity leave, and one of two that doesn’t offer sick leave to workers. Of the whole world, we’re one of two countries — us and Papua New Guinea — that don’t guarantee paid leave for new moms.” Shabo cited a survey of 185 nations by the International Labour Organization.

Vicki Shabo, vice-president of the National Partnership for Women and Families, said the San Francisco measure could help boost momentum at the national level. “It’s great to see local leaders stepping up,” she said, noting that California’s first-of-its-kind law served as a model for other states. “There’s a growing consensus that the nation must do something to address this.”

A report from Women Employed estimated 460,000 private-sector workers in Chicago don’t have access to paid sick days. Another report, from the National Partnership for Women & Families, put the number at 2.1 million people in Illinois.

“This is history in the making,” said Debra Ness, president of the National Partnership for Women & Families, who estimated that 6.4 million workers in the state who are currently without an employee-sponsored paid family leave benefit.