For a three-act plot analysis, put on your screenwriter’s hat. Moviemakers know the formula well: at the end of Act One, the main character is drawn in completely to a conflict. During Act Two, she is farthest away from her goals. At the end of Act Three, the story is resolved.
Act I
Meridian is born into a working-class family in the rural South. As a teenager, she becomes pregnant by a boy named Eddie and marries him; they have a son named Eddie Jr. This bums Meridian out for a lot of reasons, but mainly because she doesn't like Eddie much. Eventually, Eddie breaks things off and Meridian joins the Civil Rights Movement on a whim. When she gets an opportunity to attend Saxon College in Atlanta on a full scholarship, she gives Eddie Jr. away for adoption and leaves home.
Act II
A lot happens at Saxon. Meridian makes a new BFF named Anne-Marion. She also gets closer to Truman, a hunky activist whom she met back home. Then things go sour. First, Truman ignores Meridian and starts dating a white exchange student named Lynne. Then, after Meridian falls victim to a terrifying, seizure-like attack, Anne-Marion tells her that they can't be friends anymore. After hanging around in the Movement for a few years, Meridian decides to head back South and live among the people.
Act III
Meridian starts traveling between small towns and helping people. Meanwhile, her health worsens and she gets poorer and poorer. Truman still visits her occasionally; his marriage with Lynne is on the rocks. After Truman's daughter dies, he comes to visit Meridian and is finally able to understand her. At the end of the novel, we find Meridian restored to health and Truman picking up where she left off—aka, sick as a dog.