In 1970, when All My Children first appeared, Dr. Joe left California following the death of his wife,  and returned to Pine Valley with his children, Jeff and Tara.  From first meeting, he was drawn to nurse Ruth Brent, and when her husband Ted was killed in an auto accident, they began seeing one another.  They were married in 1972.

Three years later, the Martins took in Tad Gardner, who'd been thrown from a moving car and abandoned by his father, the evil Ray Gardner.  Jeff and his wife Mary (wife #2, following Erica Kane) planned to adopt the boy, but Mary was tragically killed in a burglary and Jeff moved away to escape the pain and reminders.  Joe and Ruth stepped in, and, following an attempt by Ray to sell them the child for $10K which resulted in his being jailed, they adopted Tad.

In 1976, there was trouble in paradise when Ruth and Joe clashed over the relationship between his daughter Tara and her son, Phil Brent.  Phil and Tara, the original star-crossed soap lovers, eventually married (and were more or less happy until Phil went away to war and was killed) and Ruth and Joe reconciled.  Joe was tempted by an abused patient, but his love for and devotion to Ruth kept him from straying.

In 1979, Joe and Ruth got a surprise - she discovered she was pregnant, and  gave birth later that year to the baby they named Joey (now known as Jake). 

Joe's mother, the beloved Kate Martin, passed away in her sleep in 1985, and in 1997 Joe suffered a serious heart attack.  He tried to keep the severity of it from Ruth, but she eventually discovered the truth and nursed him back to health.

While their children still periodically give them fits, Joe and Ruth remain the bedrock of Pine Valley and the ones that both relatives and friends turn to in times of trouble.