During the Cold War, America was hit by all-out nuclear panic.

May 1951 | A radiological team checks a "bombed" area for radiation after a simulated atomic bombing in Utica, New York. | (AP Photo/Arthur Z. Brooks, File)

It started in 1945, when the U.S. dropped the world's first atomic bomb on Hiroshima, killing thousands in an instant. When the Soviet Union conducted its first known nuclear test in 1949, fears of a potential nuclear war hit home. And as Cold War tensions mounted through the 1950s, anxious Americans remained on high alert.

In 1951, President Harry Truman created the Federal Civil Defense Administration (FCDA) to address the nation's existential dread. The new bureau distributed brochures, literature, and videos on how to survive nuclear fallout, often inadvertently stoking the public's worst fears.

Schools began implementing the now infamous "duck-and-cover" drills, during which teachers would scream "drop!" randomly during the school day and students would dive underneath their desks, simulating what to do in case of an airstrike. Some cities even began distributing "military-style" dog tags for children to wear to class to identify them in case of a mass explosion. New York City spent some $159,000 on such student identification.

January 1951| Elementary school students kneel in the hallway during an air raid drill being practiced by public schools in Baltimore. | (AP Photo, File)

Then came the fallout shelters.

In 1957, the FCDA — by then renamed the Office of Defense Mobilization — released the Gaither Report, which recommended the private and public construction of nuclear bomb shelters. Some families were well ahead of these recommendations, having constructed underground bunkers in their backyards and basements themselves. But following the report, the federal government began aggressively promoting these extensive physical precautions, specifying requirements for construction materials, offering instruction manuals for DIY shelters, and allocating some $169 million toward the construction of public bunkers.

Commercial businesses offered a range of shelters that met every family's needs, from a $150 refuge built into the corner of a basement to a $5,000 deluxe suite, which featured a phone, beds, and toilets.

"We owe that kind of insurance to our families and to our country," President John F. Kennedy said in a 1961 speech. "The time to start is now. In the coming months, I hope to let every citizen know what steps he can take without delay to protect his family in case of attack. I know you would not want to do less."

Americans took up the government's call with fervor.

September 1958 | Two women emerge from a new family-type bomb shelter on display in Milwaukee, Wisconsin. | (AP Photo/File)

As the Cold War dragged on and hostilities eased through the 1970s, nuclear war finally began to seem like a distant nightmare, and America's fallout fever began to break. Many of the federal and local bunker-construction programs were postponed indefinitely, and home shelters transformed into basements and recreational spaces.

Below, travel back to America's era of duck-and-cover.

March 1951 | Two styles of bomb shelters are shown for sale at Bomb Shelter Mart in Los Angeles. | (AP Photo/Don Brinn, File)

September 1961 | Bomb shelter manufacturer engineers study specifications for a fiber glass dome shelter being installed on an estate in Locust Valley, New York. | (AP Photo/File)

October 1961 | A woman and her children make a practice run for their $5,000 concrete and steel backyard fallout shelter in Fair Oaks, California. | (AP Photo/Sal Veder)

January 1959 | Pfc. Warner Bitterman, left, watches as Army chief chemical officer Maj. Gen. Marshall Stubbs, center, checks new civilian gas mask being worn by secretary Margaret Francis at his Pentagon office in Washington. | (AP Photo/File)

November 1951 | Sixth-grade students crouch under their desks with their teacher as they act out a scene from a Federal Civil Defense Administration video in Queens, New York. | (AP Photo/Dan Grossi, File)

September 1961 | A man tours a huge cavern carved 650 feet underground being leased as an emergency bomb shelter. The area included 125 rooms separated by 10-foot walls of solid salt. | (AP Photo)

January 1962 | Two families demonstrate how people would wait out a nuclear attack and its radioactive aftermath in Los Alamos, New Mexico. | (AP Photo/File)