Americans voted on an array of ballot measures on Tuesday, with South Dakota rejecting a law that would have banned almost all abortions and Arizona defeating an amendment that would have banned gay marriages.

Voters from other states considering amendments designed to prevent same-sex marriage approved the measures, however.

In Missouri, voters approved a measure that supports stem cell research after a campaign that featured a high-profile controversy involving Canadian-born actor Michael J. Fox.

A total of 205 issues were on the ballots in 37 states on Tuesday, but the ballot measure attracting the most attention was the one asking voters in South Dakota to approve or reject a law that would have allowed abortion only in cases where it would save a woman's life.

The measure was rejected by a 55 to 45 margin. The South Dakota legislature passed the law earlier this year, and legislators had hoped it would be challenged legally so the case would eventually prompt the U.S. Supreme Court to reverse the 1973 Roe vs. Wade decision that legalized abortion in the U.S.

Jay Nicolay, a leader of the campaign opposed to the ban in South Dakota, said the measure went too far.

"We believe South Dakotans can make these decisions themselves," she said. "They don't have to have somebody telling them what that decision needs to be."

Ballots cast on gay marriage

Voters in Arizona, meanwhile, refused to change the state constitution to redefine marriage as an institution between a man and a woman. Under the measure, civil unions and domestic partnerships would also have been forbidden.

Arizona was the only state to have rejected such an amendment in recent years.

In total on Tuesday, voters in eight states cast ballots on amendments that would ban gay marriage. Voters in Colorado, Idaho, South Carolina, South Dakota, Tennessee, Virginia and Wisconsin all approved the amendments.

Despite the results, Matt Foreman, executive director of the National Gay and Lesbian Task Force, said the campaign against same-sex marriage is slowly losing ground in the U.S. He said the measures to approve the amendments to ban gay marriage won by relatively small margins.

"What we're seeing is that fear-mongering around same-sex marriage is fizzling out," Foreman said.

Small margin in Missouri supports stem cell measure

In Missouri, the measure supporting stem cell research was approved by a small margin after it became an issue in the Senate race in that state, with Democratic challenger Claire McCaskill winning the seat from incumbent Republican Jim Talent.

McCaskill was in favour of the measure, while Talent was opposed to it.

Actor Michael J. Fox, who suffers from Parkinson's disease, endorsed the amendment as part of a high-profile advertising campaign, but several other celebrities were opposed to it.

According to other ballot measures results, voters in six states — Arizona, Colorado, Missouri, Montana, Ohio and Nevada — agreed to raise state minimum wages.

In Michigan, voters decided that race and gender should not be determining factors about enrolment in public universities or hiring for government work.

Arizona voters had to decide on 19 ballot measures in all. They approved one that makes English the official language in the state and another that increases the number of government benefits that illegal immigrants will not be able to receive.

Other measures on ballots around the country included banning smoking in public places, legalizing possession of up to an ounce of marijuana by anyone 21 and older, barring state governments from taking private property for private use and capping increases in state spending.

With files from the Associated Press