Karen Olson was a marketing executive writing ad copy for disposable razors and home pregnancy tests when a particular New York City homeless woman caught her eye.

“Just on impulse, I really don’t know why, but I went across the street and got her a sandwich,” Olson said. “I gave it to her and then she took my hand and told me about herself. All of a sudden, I had crossed an invisible line. These people aren’t untouchable.”

That 1980s encounter is the seed from which the nationwide homeless services network Family Promise grew. Olson is the founder and president of Family Promise, and will be in Lawrence next week to celebrate the 25th anniversary of the nonprofit organization.

“I had the perfect background for it, didn’t I?” Olson said, referencing her career as a marketing executive.

These days, Olson delivers that line with a bit of a laugh, but she wants business leaders and others to stop and think about what background it really does take to make a difference.

“I’m not a social worker,” Olson said. “I don’t have a degree in nonprofit management. What I brought to the table was compassion, some basic logic, and a whole lot of persistence.”

Family Promise, which is now operating in 182 communities and is expected to serve about 50,000 people this year, uses churches to serve as temporary shelters for homeless families.

In Lawrence, the Family Promise organization is celebrating its fifth year in existence. Joe Reitz, one of the founders of the local group, said it has grown from eight congregations originally to 35 today.

Reitz, a retired business school professor who is on Family Promise’s national board of directors, said he invited Olson to speak to the general community in Lawrence and also to business students at Kansas University because he thinks she has an important message to share.

“I’m hopeful that people take away that social problems are not necessarily best served by government solutions,” Reitz said. “At least in this country, individuals still can make a hell of a difference.”

Family Promise — based in Summit, N.J., just outside of New York City — is privately funded. But Olson said she does promote a message that it will take a joint effort between the private and public sectors to combat homelessness.

“The private sector has to be the leader in creating solutions locally,” Olson said. “But it also is important for the people involved to recognize that government is an essential partner. This cannot be solved by the private sector alone, but unless the private sector gets involved, we’ll never create the partnerships that we need to solve family homelessness.”

Olson said she ultimately decided to focus her efforts on helping homeless families, rather than the often-more-visible street homeless, because she learned that in her home state of New Jersey, homelessness was the No. 1 reason children were being removed from their parents’ care.

“It wasn’t that they were being abused,” Olson said. “It was that they didn’t have a roof over their heads.”

Plus, Olson said she thought this was an effort where her background in the business world could be useful.

“My marketing background told me that the first step had to be awareness,” Olson said. “People didn’t think of families as being homeless. They thought they were the people you stepped over in New York City.”

Reitz said the perception in Lawrence was much the same.

“The initial reaction in Lawrence was skeptical or hostile,” Reitz said of efforts to get Family Promise established locally. “There were a lot of people who had a perception that the only homeless people were the chronic homeless that they saw downtown. They didn’t understand that there were homeless families who were ready to be helped.”

Currently, the Lawrence Family Promise program houses up to five families in a single church each week. The location rotates among 13 area churches. The program also houses four to five other families in transitional housing, which are housing or apartment units that landlords rent at a discounted rate. That program started about a year ago.

Reitz said the initiative is an example of how the local Family Promise program has evolved and gained the trust of the community.

“People really have responded to the need,” Reitz said. “I think we have a reputation for getting things done effectively.”

The local program, which is overseen by executive director Dana Ortiz, also involves regular counseling and goal setting with the homeless parents, designed to get them out of homelessness.

Reitz said success stories have been frequent. He said that providing stable shelter and food to a family often gives the parents a needed “time out” to plan and reflect on the factors that led to homelessness.

Reitz said he hopes Olson’s series of talks in Lawrence gives area residents time to reflect on how they can help.

“Particularly for the students at the business school and in social welfare, I hope they walk away understanding that they not only are empowered to make a difference in the lives of an individual, but if they come up with an idea that catches on, it can help a whole lot of people,” Reitz said. “That’s what has happened here.”