It's only taken 46 years, but we might be on the verge of a new constitutional amendment.

With Illinois putting its stamp of approval on it Wednesday, the Equal Rights Amendment -- passed by Congress in 1972 -- needs only one more state to say yes before it's ratified.

Illinois' vote puts the total state tally at 37 -- one short of the required number. Which one of these brave states -- most but not all are staunchly conservative -- will be the one that puts the amendment over the top?

You can choose from Arizona, Utah, Oklahoma, Missouri, Arkansas, Louisiana, Mississippi, Alabama, Georgia, Florida, South Carolina, North Carolina or Virginia.

A supporter of the Equal Rights Amendment chants slogans with about 150 marchers who participated in an ERA walkathon in Dallas in 1981. (DMN file photo)

"I am appalled and embarrassed that the state of Illinois has not done this earlier," Democratic Rep. Stephanie Kifowit of Oswego, Ill., told the Chicago Tribune. "I am proud to be on this side of history and I am proud to support not only all the women that this will help, that this will send a message to, but I am also here to be a role model for my daughter."

If you're keeping score, Texas ratified the ERA in 1972.

The amendment, as currently written, comes in three sections: "(1) Equality of rights under the law shall not be denied or abridged by the United States or by any state on account of sex; (2) The Congress shall have the power to enforce, by appropriate legislation, the provisions of this article; (3) This amendment shall take effect two years after the date of ratification."

But if you think it only takes one more state to embed the ERA into federal law -- well, not so fast, Gloria Steinem.

There is a slight catch: Congress imposed a deadline of seven years to pass the amendment, which was later extended three years to 1982.

Women opposed to the Equal Rights Amendment sit with Phyllis Schlafly (left) national chairman of Stop ERA, at hearing of Republican platform subcommittee on human rights and responsibilities in a free society in 1976 in Kansas City, Mo. Schlafly was credited with helping mobilize public opinion against the amendment in some of the states that balked at ratifying it in the early years of its existence. (AP)

So, thanks for all the hard work, Illinois, but you missed the deadline by 36 years.

If Congress holds fast to that deadline, expect myriad legal challenges, Matthew Haag of The New York Times writes.

"Supporters say that the 27th Amendment shows that Congress should not have imposed a deadline on the E.R.A. Since 1992, they have argued there are several ways to make the amendment viable, which they wrapped into something called the "three-state strategy" before the [most recent] votes in Nevada and Illinois," Haag writes.

Congress could simply vote to change the deadline, Haag says, or it could really clog the gears by writing an entirely new amendment, which would requite the ratification process to start all over again.

The Chicago Tribune, The New York Times and CNN contributed to this report.