(CNN) - When officials in Baton Rouge, Louisiana, refused to make black history part of the mandatory school curriculum, Sadie Roberts-Joseph created a museum dedicated to African-American heritage, friends say.
Today, the Baton Rouge African-American Museum occupies a four-room building under Interstate 10. It was first named for educator Odell S. Williams, whose paintings of black inventors adorn the museum's walls. A bus outside tells the story of the Baton Rouge bus boycott during the Civil Rights era. A room inside has pictures of Barack Obama's inaugurations.
The museum was Roberts-Joseph's "love letter" to Baton Rouge, a way for her to share black history with young people, museum volunteer Myra Richardson said.
The slaying of the 75-year-old activist has left the museum in limbo -- she was largely responsible for operating the facility -- and shaken the people of Baton Rouge who knew her.
"It was a shock to all of us that somebody could even do this to her, that somebody could have such a disregard for life -- especially her life," Richardson said.
'She embodied our culture'
Known as "Ms. Sadie," Roberts-Joseph was fascinated by black history, friends and family told CNN.
She had one foot in the past and the other in the present and she worked to bridge the two in a way that would educate the young people of her city.
'"That was her life's work. That was her manifesto," said Richardson, a 20-year-old student at Southern University and A&M College in Baton Rouge, Roberts-Joseph's alma mater. "The museum was an extension of who she was. She embodied our culture. She embodied freedom."
Richardson said Roberts-Joseph shared her hopes for the museum weeks before her death.
The two sat inside the bus boycott exhibit outside the museum, designing fliers for Juneteenth, another celebration of black history in Baton Rouge that Roberts-Joseph was responsible for.
They spoke for hours as Roberts-Joseph laid out her vision for the museum. She hoped to modernize it and start a bookmobile of works by black authors, said Richardson, a social justice activist.
It was their last conversation.
Last Friday, Roberts-Joseph's body was found in the trunk of her car, about three miles from her home, after an anonymous caller reported finding her, police said.
Earlier in the day, she had been making cornbread with her sister, said Pat LeDuff, a niece.
Ronn Jermaine Bell, 38, a tenant in one of Robert-Joseph's rental homes who was behind on his rent, was charged killing her, Baton Rouge police said.
The East Baton Rouge Parish Coroner's Office had determined the preliminary cause of death was "traumatic asphyxia, including suffocation."
A historian at heart
Roberts-Joseph was the fifth of 12 children born to sharecropper parents in Woodville, Mississippi, said her brother, Joseph Armstrong, 82.
The children divided their time between a one-room schoolhouse and the cotton fields. No matter where she was, Roberts-Joseph looked for answers, he said.
"She always had a lot of questions about what was going on, the why and how," said Armstrong, a pastor.
Roberts-Joseph worked for decades as a certified respiratory therapy technician at the now-closed Earl K. Long Medical Center, LeDuff said. She once ran community center.
But she was historian at heart, finding ways to make family gatherings or holidays into a lesson.
"She was the teacher of our family, always educating us, always making us aware of things," LeDuff said. "If you were saying something that wasn't factual, she would make sure that you know what you were saying is wrong."
An emphasis on young people
In 1993, after LeDuff's 19-year-old brother was accidentally shot, the family started the nonprofit Community Against Drugs and Violence with Roberts-Joseph as its president.
The organization provided the community with information about free resources such as school uniforms, tutoring and summer camps.
Roberts-Joseph encouraged mentoring young people, her niece said. She encouraged them to stay in school, to find a job and be self-sufficient, believing they were the key to a peaceful, prosperous future.
"All my mother ever wanted was for this community to come together. It's ironic that that happened in death," Roberts-Joseph's daughter, Angela Machen, told reporters after Bell was charged. "What she wanted to happen in life came to fruition in death. However, we will see to it that her legacy continues."
The museum was part of Robert-Joseph's effort to nurture children into leaders, her brother said.
"She always thought if you don't know where you come from, you don't know where you're going," he said. "Her main goal was to get people to learn their history."
Museum founded in 2001
The state of public education was a driving force for Robert-Joseph to launch the museum, said Patricia Haynes Smith, a Democratic member of the Louisiana House of Representatives.
Smith said the two met in the early 1990s in city council and state legislature meetings, where Robert-Joseph was a regular fixture.
Wearing elegant African garb and an infectious smile, she brought a "quiet power" to causes she advocated for, including black history education, Smith said.
After retiring, Roberts-Joseph opened the museum in 2001 in the former sanctuary of the church where her brother was pastor. It is now in a nearby location. She ran it on her own for years with the help of grants and volunteers. The church pays for the utilities, her brother said.
"It took an act of God for her to go on with the museum like she did," Armstrong said.
'She was about building relationships'
Outside the museum, she planted cotton as a symbol of a not-so-distant era of the past. Inside, she filled the rooms with items she acquired over the years. Each piece had a story. And she knew them all by heart.
One room paid tribute the history of African-Americans in Louisiana. Another featured artifacts from African nations, such as drums and masks. Another room celebrates President Obama and African-American veterans.
She hosted community events at the museum, including events to strengthen the relationship between the police and the community, LeDuff said. "She was about building relationship, getting along, working together, coming together," LeDuff said.
She encouraged schools to bring young people to the museum and gave tours to anyone who came through.
"She would always say 'it's not black history. It's American history,' " LeDuff said.
Correction: A previous version of this story incorrectly stated where Roberts-Joseph was born. She was born in Woodville, Mississippi.
CNN's Michaela N. Vincent contributed to this report.
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