It is only in the last one hundred years that the custom of the nuclear family become widespread. Most of the immigrants to America, such as those from lreland and ltaly, also had the custom of the extended family, and when most Americans made their living as farmers, it was easy for the extended family to stay together. However, since most people in industrial countries now work for some kind of business, and since it is so common to move to a new city to get a good job, now people in these countries frequently live only with their own spouses and children.