American families are different today than they were 100 years ago. The biggest difference is that they are smaller. In the past, most families lived on farms. They needed lots of children to help with work. Today, most families live in cities, and many parents cannot afford a large family. Other parents worry that if they have more than two children, it will increase the world’s population. 

　　Also, the types of families are changing. There are more single parents than ever before. More unmarried couples are having children, and many couples are choosing to have no children at all. Today traditional families – a married couple with children – compose less than 25 percent of all US households. 

　　One reason for this is the greater number of working women. In the past, women depended on their husbands. Now many women have jobs. They do not have to be married to get money. Another reason is divorce. This is when the husband and wife decide to end their marriage. About half of all US marriages end in divorce. Finally, many people are not getting married. They choose to live their lives by themselves.