In 1998, the District of Columbia Public Schools were doing such a bad job preparing students for college that when local business executives asked how many graduating seniors went to college the year before, district leaders didn’t know.

Dismayed, the business people took action. They set up a privately financed college counseling organization for D.C. neighborhood schools, whose 12th-grade counselors had neither the time nor the expertise to handle college application issues. The regular counselors had to focus on kids with serious personal problems, such as flunking courses, missing school and being homeless.

The business-funded effort was called the D.C. College Access Program, DC-CAP. Before it was born, only about a third of seniors even tried college. Only about 15 percent of former D.C. students received college degrees.

This year, after two decades of work by DC-CAP, about two-thirds of D.C. graduates — close to the national average — go to college. About half of them graduate within six years. The numbers need to be better, but D.C. has come a long way.

Leading that effort as DC-CAP president and chief executive has been Argelia Rodriguez, a visionary who previously ran her own educational and management consulting firm for universities, companies, associations and the D.C. public schools. DC-CAP has benefited from her determination to get things done and her diplomatic skill working with D.C. administrators often tired of hearing from outsiders what they were doing wrong.

Now, Rodriguez has announced what she calls her graduation from DC-CAP. She plans to step down at the end of the school year. How did she and her staff make such progress?

Her organization emerged at a time of great ferment in the effort to make college real for impoverished teenagers. When I first wrote about DC-CAP in 2003, I noted several small groups trying to help, including College Bound, Hoop Dreams, the Urban Alliance Foundation and the Coaching for College Program. The arrival of Rodriguez, her crew and their private supporters gave such efforts a huge boost.

Donald E. Graham, then chair of The Washington Post Company board, led the DC-CAP board. He and his many allies pointed out to Congress how unfair it was that D.C. students, alone in the country, were unable to go to a state university and pay in-state tuition. They could go to the University of the District of Columbia, but that was not the right college for many of them.

Graham recalled recently how amazed he was to see Congress unanimously pass in 1999 the D.C. Tuition Assistance Grant program. Today it gives D.C. students up to $10,000 to pay the difference between in-state and out-of-state tuition at public universities around the country, or gives them $2,500 a year if they attend a historically Black college or university or any D.C. area college. In addition, DC-CAP awards as many $2,500 scholarships as it can afford.

The business group began by creating a $15 million endowment for DC-CAP. It opened college information centers and placed full-time college advisers in D.C. public schools, roughly doubling the number of college counselors available. It employed what it called retention advisers to help students stay in college.

In 2003 I interviewed Rashidah Sabree, a bright student who looked unlikely to get into any college before DC-CAP found her. She had not taken the SAT. When DC-CAP made that happen, her scores were terrible — 320 in math and 340 in verbal skills.

Her DC-CAP advisers, undaunted, helped her prepare her application to Delaware State and convinced her she could succeed despite her lousy scores. She got in, but that was just the beginning of her struggle.

She was a vibrant young woman who had enjoyed Washington’s nightlife. The city of Dover, where her Delaware State campus was located, was the state capital, but was tiny and drab compared with the nation’s capital. Sabree told me: “The first year I hated it. I wanted to come home. I was homesick.”

To fight that feeling, her advisers, Pamela Brown and Andrea Linthicum-Seymour, helped her with financial problems and told her often that everything would get better if she worked at it. Eventually she realized she was there for an education, not entertainment.

Linthicum-Seymour explained to me a vital part of the DC-CAP approach. Students like Sabree had parents who had never gone to college. Her father was a construction worker and her mother a bank teller. Neophyte undergraduates like her needed to believe firmly that their tuition dollars entitled them to the same services that middle-class college students received, and to complain when their colleges dropped the ball.

When D.C. students got to college, Linthicum-Seymour said, they were “often afraid to speak up or afraid to ask for help. I provided a medium for Rashidah to be able to express herself.” It was also important that the D.C. schools provided more challenging courses, such as Advanced Placement, to prepare students for higher education.

DC-CAP has helped enroll more than 35,000 students in college, of which 14,000 have gotten degrees and 6,700 are still in school. It has awarded nearly $55 million in scholarships and helped develop techniques such as raising students’ personal expectations. Retention advisers are now employed by many organizations across the country.

The companies who founded DC-CAP included AES Corp., AOL, the Morris & Gwendolyn Cafritz Foundation, ExxonMobil, the Fannie Mae Foundation, the Greater Washington Urban League, Lockheed Martin, Marriott International, the Catherine B. Reynolds Foundation, Riggs National Corp., Sallie Mae, Charles E. Smith Cos., Verizon and The Washington Post Co.

Rodriguez said that “we created a college-going culture among D.C. students and families where higher education is the expectation, not the exception.”

Sports and business magnate Ted Leonsis, now the DC-CAP board chair, said that because of Rodriguez’s “passion and leadership, we are in an excellent position to continue this critical work.”

The organization’s counseling function has been reduced as the D.C. schools have invested more in that responsibility. What is needed, its leaders say, is larger scholarships to keep up with rising out-of-state tuitions.

DC-CAP is also looking more closely at which colleges have the best graduation results. That can have an effect not just on D.C. students, but also on young people from low-income families all over the country who deserve better educations than they are getting.