Born William Jr., Snapper resented being named after his father who had walked out on the family, so he was called “Snapper” after his not-so-winning personality instead. Snapper not only put himself through medical school with a part-time job, but also, as the man of the family, contributed to Greg Foster’s law school tuition and kept a eye on little sister Jill Foster.
Liz encouraged Snapper to pursue Chris Brooks, daughter of the publisher of the Genoa City Chronicle. But Snapper preferred his freedom, so while he was dating Chris, he slept with Sally McGuire. Chris's father learned that Snapper was seeing Sally and told Chris that Snapper was cheating on her. Chris moved out of Snapper's house and went to work for Greg. Chris later met George Curtis who offered to walk her home and then raped her. Months later Chris was willing to make love with Snapper, but memories of the rape still haunted her. Snapper was understanding and supportive, but he still had Sally on the side.
Sally had also fallen in love with Snapper, so she stopped using birth control pills and got pregnant by him. However, Snapper broke up with Sally and proposed to Chris. A long while later Chris finally accepted. The pregnant Sally was devastated to hear of this. Sally told her boss, Pierre Roulland, that she was pregnant. Since he was in love with her he offered to marry her and give the baby his name. Sally accepted Pierre's proposal and they eloped a few days before Snapper's wedding. Chris and Snapper worked through her sexual problems and happily lived in a small apartment. But when Chris became pregnant, Snapper feared that the additional responsibility might set back his medical career.
Sally had finally appreciated Pierre and had fallen in love with him, but Pierre was tragically killed by a robber. Sally wanted to leave town but Snapper urged her to stay until the baby was born. Sally gave birth to a healthy baby boy and named him Pierre Charles Roulland, but called him Chuckie. Chris had a miscarriage herself when eventually realized that Snapper was the baby's father and she and Snapper separated.
Snapper then fell for Dr. Casey Reed. Their relationship did not last because Casey had a fear of sex due to being sexually abused by her father as a child. Sally sold the restaurant and moved, and Chris and Snapper reconciled.
Snapper finally convinced Liz to have Bill declared legally dead, but then Bill sent a letter to the family. Liz invited Bill to move back into the house. Although Bill realized that he still had feelings for Liz, he put her needs above his own and encouraged Liz to continue with her plans to marry Sam Powers. But Liz broke off her engagement to Sam because she was still a married woman. Bill and Liz remarried, and Snapper and his father finally reconciled, but Bill's cancer progressed quickly and the doctors doubted that he would live out the year. Bill was hospitalized and put on life support. He pleaded may times with Liz to pull the plug and Liz agreed to obey his wishes. But she was so traumatized by doing so that she suffered a stroke and forgot that she did it. Snapper was accused of killing his father. Luckily Greg was now a practicing lawyer who got Snapper was cleared of murder charges, and Liz was never charged.
Snapper and Chris had a baby girl, Jennifer Elizabeth Foster. Soon after, Sally returned to Genoa City with Chuckie, who was seriously ill. While Chuckie was hospitalized for a kidney operation, Sally urged Snapper to tell Chuckie that he was his father, but Snapper decided against it.
In 1982, Snapper left Genoa City to accept a three-month fellowship opportunity in London, but Chris refused to give up her Jabot modeling career. Not long afterward, she realized her place was with Snapper and joined him in London. Liz, Stuart Brooks (Liz's husband), and Greg moved to London as well by the end of the year.
In 2003, Liz arrived in Genoa City with Snapper and Greg from their home in England with the news that she was to undergo brain surgery. Knowing she may not survive, Liz felt it was time to admit to Jill that she was adopted.
In 2010, Snapper and Liz came to town to visit Jill, but Liz collasped on the plane and was rushed to the hospital. Knowing that she was really going to die, Liz told Snapper who Jill's parents were, but begged him not to tell. Snapper agreed, but told Jill after Liz died. He left town shortly after.