Almost exactly nine months after World War II ended, “the cry of the baby was heard across the land,” as historian Landon Jones later described the trend. More babies were born in 1946 than ever before: 3.4 million, 20 percent more than in 1945. This was the beginning of the so-called “baby boom.” In 1947, another 3.8 million babies were born; 3.9 million were born in 1952; and more than 4 million were born every year from 1954 until 1964, when the boom finally tapered off. By then, there were 76.4 million “baby boomers” in the United States. They made up almost 40 percent of the nation’s population.

The Baby Boom

What explains this baby boom? Some historians have argued that it was a part of a desire for normalcy after 16 years of depression and war. Others have argued that it was a part of a Cold War campaign to fight communism by outnumbering communists.

Did you know? In 1966, Time magazine declared that “the Generation Twenty-Five and Under” would be its “Persons of the Year.”

Most likely, however, the postwar baby boom happened for more quotidian reasons. Older Americans, who had postponed marriage and childbirth during the Great Depression and World War II, were joined in the nation’s maternity wards by young adults who were eager to start families. (In 1940, the average American woman got married when she was almost 22 years old; in 1956, the average American woman got married when she was just 20. And just 8 percent of married women in the 1940s opted not to have children, compared to 15 percent in the 1930s.)

Many people in the postwar era looked forward to having children because they were confident that the future would be one of comfort and prosperity. In many ways, they were right: Corporations grew larger and more profitable, labor unions promised generous wages and benefits to their members, and consumer goods were more plentiful and affordable than ever before. As a result, many Americans felt certain that they could give their families all the material things that they themselves had done without.

Moving to the Suburbs

The baby boom and the suburban boom went hand in hand. Almost as soon as World War II ended, developers such as William Levitt (whose “Levittowns” in New York, New Jersey and Pennsylvania would become the most famous symbols of suburban life in the 1950s) began to buy land on the outskirts of cities and use mass-production techniques to build modest, inexpensive tract houses there. The G.I. Bill subsidized low-cost mortgages for returning soldiers, which meant that it was often cheaper to buy one of these suburban houses than it was to rent an apartment in the city.

These houses were perfect for young families–they had informal “family rooms,” open floor plans and backyards–and so suburban developments earned nicknames like “Fertility Valley” and “The Rabbit Hutch.” By 1960, suburban baby boomers and their parents comprised one-third of the population of the United States.

The Baby Boom & The “Feminine Mystique”

The suburban baby boom had a particularly confining effect on women. Advice books and magazine articles (“Don’t Be Afraid to Marry Young,” “Cooking To Me Is Poetry,” “Femininity Begins At Home”) urged women to leave the workforce and embrace their roles as wives and mothers. The idea that a woman’s most important job was to bear and rear children was hardly a new one, but it took on a new significance in the postwar era. First, it placed the baby boomers squarely at the center of the suburban universe. Second, it generated a great deal of dissatisfaction among women who yearned for a more fulfilling life. (In her 1963 book “The Feminine Mystique,” women’s-rights advocate Betty Friedan argued that the suburbs were “burying women alive.”) This dissatisfaction, in turn, contributed to the rebirth of the feminist movement in the 1960s.

The Boomer Market

Consumer goods played an important role in middle-class life during the postwar era. Adults participated eagerly in the consumer economy, using new-fangled credit cards and charge accounts to buy things like televisions, hi-fi systems and new cars. But manufacturers and marketers had their eyes on another group of shoppers as well: the millions of relatively affluent boomer children, many of whom could be persuaded to participate in all kinds of consumer crazes. Baby boomers bought mouse-ear hats to wear while they watched “The Mickey Mouse Club” and coonskin caps to wear while they watched Walt Disney’s TV specials about Davy Crockett. They bought rock and roll records, danced along with “American Bandstand” and swooned over Elvis Presley. They collected hula hoops, Frisbees and Barbie dolls. A 1958 story in Life magazine declared that “kids” were a “built-in recession cure.” (“4,000,000 a Year Make Millions in Business,” the article’s headline read.)

The Boomer Counterculture

As they grew older, some baby boomers began to resist this consumerist suburban ethos. They began to fight instead for social, economic and political equality and justice for many disadvantaged groups: African-Americans, young people, women, gays and lesbians, American Indians and Hispanics, for example. Student activists took over college campuses, organized massive demonstrations against the war in Vietnam and occupied parks and other public places. Young people also participated in the wave of uprisings that shook American cities from Newark to Los Angeles in the 1960s.

Other baby boomers “dropped out” of political life altogether. These “hippies” grew their hair long, experimented with drugs, and–thanks to the newly-accessible birth-control pill–practiced “free love.” Some even moved to communes, as far away from Levittown as they could get.

Baby Boomers Today

As baby boomers age, the population of seniors in the United States increases. By 2030, about one in five Americans will be older than 65, and some experts believe that the aging of the population will place a strain on social welfare systems.