They planned their incursion at the U.S. Capitol Tuesday afternoon.

Even though no one had deployed this particular gambit in more than 18 years.

Still, the strategy was familiar. A clutch of Democratic, female, House lawmakers would mass on friendly ground and then initiate a raid behind enemy lines.

In this case, the sortie would carry them across the Capitol Rotunda and into the heart of the evil empire: the U.S. Senate. And there, the women would plead their case for the Senate to break a Republican filibuster and muscle the Paycheck Fairness Act onto the floor.

Supporters of the package designed the bill to guarantee equal earnings for men and women doing the same jobs. And the Senate required a supermajority of 60 senators just to clear the first procedural hurdle so senators could debate the issue.

Sixty votes was a long shot. But that didn’t stop Reps. Rosa DeLauro (D-CT), Jan Schakowsky (D-IL), Shelley Berkley (D-NV), Donna Edwards (D-MD), Suzanne Bonamici (D-OR) and Del. Donna Christensen (D-VI) from marching to the Senate.

The effort to bring up the bill for debate failed, snaring only 52 yeas. Senate Majority Leader Harry Reid (D-NV) voted no so he could be on the “prevailing” side of the issue. Senate rules permit lawmakers who vote on the winning side to demand a future vote.

Otherwise, senators strictly cast their ballots along party lines.

The legislative effort fizzled. But the foray by female House members onto what remains the male-dominated turf of the Senate had a distinctly different feel than when it was last tried in 1994.

For one, a man joined the women in the Senate excursion: Rep. Chris Van Hollen (D-MD). Lilly Ledbetter was also along for the charge. Ledbetter is the namesake of the Lilly Ledbetter Fair Pay Act. She’s a former Goodyear supervisor who sued after she determined she earned significantly less than her male colleagues. President Obama made Ledbetter’s bill the first piece of legislation he signed into law after assuming office in 2009.

The female lawmakers immediately held an impromptu chat with reporters in the Ohio Clock Corridor once they arrived in the Senate. When the vote began, chamber security staff escorted the female House members into the Senate where fellow lawmakers welcomed them. They sat on a bench toward the rear of the chamber. Sen. Ron Wyden (D-OR) walked over to give Bonamici a hug. Sen. Jeff Merkley (D-OR) came by to say hi as well. Sen. Debbie Stabenow (D-MI) shook hands with Schakowsky and greeted Berkley. Sen. Barbara Boxer (D-CA) chatted up Berkley and Schakowsky. Sen. Barbara Mikulski (D-MD) gave DeLauro a hug. Reid talked to his fellow Nevadan Berkley. The audience with Reid was casual. In fact it was Reid who walked to the rear of the chamber to speak to the group of women.

The women didn’t get the outcome they wanted with the vote. But their reception in the Senate was a lot different than in 1994. Or certainly 1991.

It’s rare for a throng of female House members to execute an organized march over to the “World’s Greatest Deliberative Body.” But previous advances didn’t go over so well. And the general ease and lack of drama surrounding Tuesday’s visit was a subtle footnote, demonstrative of how much things have changed.

It was also a Tuesday in October, 1991 when a posse of seven, Democratic, female House members cruised over to the Senate to express their grievances. The Senate practices a long-standing tradition on Tuesdays. The body recesses at 12:30 pm sharp so members can retire to weekly party caucus luncheons. The Democrats all huddle in one room and Republicans do the same in another.

There were only two female senators in 1991: Mikulski and former Sen. Nancy Kassebaum (R-KS). And the issue that drove these Democratic Congresswoman to the sister body was the nomination of Supreme Court Justice Clarence Thomas. The House members called on their Senate counterparts to delay Thomas’s confirmation vote. They implored the mostly-male body to restart the hearings and give law professor Anita Hill a chance to make her allegations of sexual harassment.

Then-Rep. Pat Schroeder (D-CO) led the march to the Senate alongside Rep. Louise Slaughter (D-NY). They were joined by Boxer (who was then a House member), Rep. Nita Lowey (D-NY), then-Rep. Jolene Unsoeld (D-WA), the late Rep. Patsy Mink (D-HI) and Del. Eleanor Holmes Norton (D-DC), the capital city’s non-voting delegate to Capitol Hill.

The women found the room where Senate Democrats huddled behind closed doors. And were told they couldn’t enter.

Undeterred, they rapped at the door again.

“We were told that nobody ever gets in there,” fumed Slaughter to the New York Times. “Certainly not women from the House.”

Finally, a staffer with  then-Senate Majority Leader George Mitchell (D-ME) informed the band of women he’d meet with them after the conclave.

1991 may not have been that long ago. But it was practically a different epoch when it came to the role of women on Capitol Hill.

Even though the women weren’t admitted to the confab, they got their way. The Senate postponed Thomas’s confirmation vote. The Judiciary Committee re-opened the hearings and called Hill as a witness. And the term “sexual harassment” quickly entered the American vernacular.

The Senate finally confirmed Thomas. But that 1991 Senate trek helped set something in motion.

The Senate was often referred to as an “old boys club” in 1991. First elected in 1978, Kassebaum was the first female senator who hadn’t first been appointed to fulfill the waning days of a term left over from a deceased husband. Only 13 women had ever served in the Senate before her.

But that quickly changed. The Hill-Thomas contretemps helped fuel the “year of the woman” at the polls in 1992. Kassebaum continued her service in 1992 and voters re-elected Mikulski. They also elected four women to the Senate. The group included Boxer along with Sens. Dianne Feinstein (D-CA), Carol Moseley-Braun (D-IL) and Patty Murray (D-WA). Sen. Kay Bailey Hutchison (R-TX) won a Senate seat in a 1993 special election.

The ranks of women in the Senate eventually swelled to the 17 who serve today.

But in April, 1994, the Senate got another “House” call.

Senators wrestled with whether they should strip two of the four stars belonging to Adm. Frank Kelso, the Chief of Naval Operations. They mulled whether they should slash his pension after his 38-year career. Kelso came under fire following the Tailhook scandal. The Navy punished more than 100 of its aviators for charges of sexual misconduct and shenanigans at the Tailhook Association’s meeting in Las Vegas. Many asked whether Kelso presided over a Navy which permitted such behavior. The ignominy forced Kelso to retire early. And the Senate ultimately voted to grant Kelso his full retirement.

But this was 1994. Not 1991.

Kassebaum put out a statement that Kelso “demonstrated a failure of leadership.” Feinstein asserted that Kelso’s flag staff “protected” him.

“We are no longer content to stand by and watch women treated as less than equal citizens,” protested Moseley-Braun.

Even though there was a growing compliment of women in the Senate, female House members felt it was time for back up. A brigade of nine women again trudged over to the Senate. This time, there was Schroeder, Slaughter, Maloney, Norton and Lowey – to be joined by Rep. Lynn Woolsey (D-CA) and then-Reps. Elizabeth Furse (D-OR), Barbara Kennelly (D-CT) and Karen Shepherd (D-UT). They stood in solidarity behind their former House colleague Barbara Boxer as she delivered an impassioned speech demanding sanctions for Kelso. In a rare move, the Senate-controlled TV cameras refocused its shot to reveal the female House members standing at the rear of the chamber. C-SPAN2 telecast the image to the nation.

The plan to create pay parity between and women fell well short of the 60 vote threshold Tuesday. All five of the Senate’s Republican women voted no.

“It will be part of the decision about how (people) are going to vote in November,” predicted Schakowsky. “The women are watching.”

Women certainly watched after the 1991 female House offensive into the Senate. The 1994 march to the Senate failed to prompt any tangible legislative or electoral benefit.

But female, Democratic House members reverted to the old playbook Tuesday afternoon. And as Schakowsky says, their goal is to convert 2012 into a mirror image of 1992’s “year of the woman” in politics.