The main parent characters, Steven and Elyse Keaton married in the 1960's and started a family residing in Columbus, Ohio.  They had three children, Alex, Mallory and Jennifer.
 
Although, the parents had grown up to develop very liberal views on life, their children did not take on the same beliefs, especially their son Alex who was highly conservative and had no issue expressing his views about various topics related to politics.
 
Their daughter Mallory cared about nothing besides boys, shopping and being a teenager.  Their third daughter, Jennifer was the most sweet and innocent of the three.  Later in the series, the couple gave birth to their fourth child, a little boy, Andrew.
 
Each episode revolved around a situation in the children's lives and what issues came up during their teenage years as well as situations with how the parents had to deal with 4 kids with different personalities.   

Family Ties Intro