More than 50 years after Australian legislation providing for civil marriages, and 40 years after the first celebrant was appointed by Murphy, two American jurisdictions have finally followed suit - thanking the Labor stalwart as the father of secular weddings.

Last month New Jersey Governor Chris Christie signed legislation allowing properly certified civil celebrants to solemnise marriages and civil unions. The District of Columbia introduced a similar law late last year.

Civil celebrants officiated at nearly 72 per cent of Australian weddings in 2012. In contrast, US weddings can be conducted only by a member of the clergy in half of America's 50 states. In the other half, they must be solemnised by either ministers of religion or holders of public office, such as judges.

To get around these restriction, US civil celebrants have to be licensed as clergy. These ''civil celebrants'' must become a minister of religion, which they can do online through numerous unusual religious organisations for as little as $25, or they can take out a one-day licence as a government officer.

Australia's Dally Messenger, now 76 and semi-retired, has presided over about 6000 weddings since he was appointed the 17th civil celebrant in the 1970s.

In 2002, when he was in New Jersey training American celebrants he was required to become a minister of religion to marry couples.

''I became clergy of universal brotherhood, a registered religion, whose only belief was service to fellow man,'' Mr Messenger said.

The executive director of Centre for Inquiry Indiana, Reba Boyd Wooden said opposition to secular weddings was so great that she could not even get a member of her state's legislature to introduce legislation.

Her organisation, which fights for secular rights, has taken legal action against the state. In court, a judge asked: ''What's the big deal? Just declare yourselves a religion. Anyone can go online and do that.''

''We won't do that because we are fighting for a principle,'' Ms Wooden said. ''The big deal is you shouldn't have to pretend to be religious.''

The civil celebrant program, which began in Australia, was almost entirely the result of one man's vision, Mr Messenger writes in his book Murphy's Law and the Pursuit of Happiness.

''Murphy was opposed by his own staff, the public service, his fellow members of parliament and officials of the Labor Party. He defied all, and on July 19, 1973, in the dead of night, typed the first appointment himself, found the envelope and stamp, walked to a post box and posted it himself,'' Mr Messenger writes.

Murphy had been appalled by the assembly line civil weddings offered at registered offices.

The first weddings performed by Mr Messenger were shotgun weddings. Since then, the average age of brides has risen from 19 to 29, and ceremonies have expanded to include poetry, music and other meaningful rituals.

Mr Messenger said civil marriages had contributed to Australia's recent drop in the divorce rate because they prompted couples to examine their relationship and commitment.

Although he has been married three times, and has married 6000 couples, Mr Messenger is not cynical.

''I've seen mothers of three or four in white wedding dresses face the partners they've been living with for eight or nine years, and repeat their vows with tears streaming down their faces,'' he said. ''You don't get too cynical when you see a lot of that stuff. My experience has been from day one that people are so grateful to have had a meaningful event.''