WASHINGTON — Two years ago last May, Jim Ramstad, a veteran congressman from the suburbs of Minneapolis-St. Paul, paid a quiet visit on a colleague whose drug abuse –– plus a harshly publicized car crash on Capitol Hill –– had just landed him in rehab at Minnesota’s Mayo Clinic.

What drove the 60-year-old Republican to pay respects to Rep. Patrick J. Kennedy –– a prominent, younger Democrat whom he did not know very well –– was the memory of his own wake-up call in a Sioux Falls, S.D., jail cell almost 25 years earlier. As Ramstad has said thousands of times to anyone who will listen to his message about alcoholism and drug addiction, “I am living proof that treatment works.”

On Friday their partnership in recovery bore fruit that Kennedy and Ramstad could hardly have imagined that spring day at the treatment center. Their bill to advance medical coverage for millions of the addicted and mentally ill was enacted after congressional action as dramatic as it was improbable.

The Kennedy-Ramstad bill, requiring insurers to cover mental illness on a par with physical illness, was a last-minute attachment to the $700-billion financial rescue that passed the House on a 263-to-171 vote. President Bush promptly signed it into law.

“This legislation is one more step in the long civil-rights struggle to ensure that all Americans have the opportunity to reach their potential,” Kennedy said. “For far too long, health-insurance companies have used the stigma of mental illness and substance abuse as an excuse to deny coverage for those biological disorders.” Ramstad, too, applauded the House action as promising hope to the mentally ill.

Gratifying as yesterday’s action was for Ramstad and Kennedy, the enactment of mental-health parity was the furthest thing from a two-man show.

The roots of the legislation reach at least as far back as the early career of Sen. Paul Wellstone, a former Minnesota college professor whose brother had suffered from serious mental illness. Democrat Wellstone teamed up on mental-health issues with Sen. Pete V. Domenici, a New Mexico Republican whose grown daughter had schizophrenia. They spearheaded a limited breakthrough for mental-health insurance parity in 1996, but efforts to expand it have since been blocked repeatedly.

The current campaign took shape after the 2006 elections when Sen. Edward M. Kennedy, Domenici, and Sen. Mike Enzi, R-Wyoming, quietly found a consensus among top representatives of the interest groups with a stake in the issue — mental-health advocates, the health-insurance industry, and businesses intent on addressing the matter for their employees. When they unveiled their approach early last year, it had the backing of a disparate coalition with substantial clout across the political spectrum. The Domenici-Kennedy-Enzi parity bill cleared the Senate without dissent last September.

Ramstad and Patrick Kennedy, meanwhile, channeled their personal experience of recovery into the legislative campaign. Early last year, they staged a nationwide series of hearings — including one in Providence — on mental-health insurance gaps. Invariably, the two contrasted the plight of the suffering under-insured with their own good fortune to have had health coverage that covered their addiction treatment. (Kennedy was also treated for bipolar disorder.) They produced a more generous bill than the Senate’s, including, for example, a long list of covered ailments that business groups opposed on grounds of expense.

Their bill passed the House overwhelmingly last March, to the consternation of mental-health champions such as Domenici, who feared it would shatter their business-health care coalition. But gradually the two sides found compromise. They dropped the diagnostic list to mollify the Senate, but kept strong House language to let the mentally ill seek treatment outside their managed care “networks.”

The legislation required insurers to offer mental-health coverage equal in cost and scope to their coverage of physical illness or injury. For example, they could no longer impose higher deductibles or copayments for mental-illness treatment. Likewise barred would be lower reimbursement ceilings for doctors and other professionals.

After a deal was struck on the policy details of parity, a long dispute ensued over how to cover the cost. The payment question was resolved as part of a deal that folded the parity bill into a popular package of tax provisions, but the bill stalled over differences between the House and Senate on unrelated budget procedures.

As the emergency market rescue bill overshadowed the congressional rush to adjournment, the mental-health bill became endangered. As recently as Sunday night, Kennedy said he was down to one last “Hail Mary pass.” That gambit was in doubt when –– “totally out of the blue,” Kennedy said — Senate leaders attached the tax-and-parity deal onto the financial rescue late Tuesday night. The massive package — parity on board — cleared the Senate late Wednesday night on a vote of 75 to 24. The only senator absent was Patrick Kennedy’s father, who has been under treatment for brain cancer since last spring. Senator Kennedy was at home on Cape Cod but still involved by phone in the jockeying for parity.

In the House, Kennedy was assigned to convert fellow Democrats who had opposed an earlier version of the market rescue. At the party caucus Thursday night, he joked about the parliamentary quirk that attached the giant rescue bill to an obscure bill that bore his name. Friday morning Ramstad and several other colleagues ribbed him about his authorship of “the $700-billion Kennedy bailout bill.”

Then there were the poignant greetings from colleagues — some with their own family horror stories about untreated alcoholism or schizophrenia — who simply stopped to hug Kennedy or drew him out of the crowd for a quiet word of thanks.

The decisive vote began as members filled the House chamber after lunch. Kennedy had cast his vote (“Yea”) and was mingling with colleagues when applause erupted in the chamber 1:22 p.m. The roll call had reached a majority for passage of the bill.

As he walked from the Capitol to his office across Independence Avenue, Kennedy contemplated the milestone for mental health that was entering the statute books under his name — and those of some of his dearest associates.

“My first thought is what a wonderful thing it is for so many people. It eliminates the stigma attached to mental illness and obviously it eliminates the discrimination imbedded in the law,” he said.

“But on a personal level, clearly, savoring this victory with my father at this point in our lives — at this moment in his life — is a dream come true.” Kennedy said. “It nearly broke my heart to think that we wouldn’t have time to get it done with him, and to celebrate it with him in the way that we are now going to be able to celebrate it.”

jmulligan@belo-dc.com