On July 4, the United States will celebrate its 250th birthday. Over the past two and a half centuries, American society has changed profoundly, from an agrarian republic of 13 colonies to the urban, diverse, and economic superpower it is today. To mark the quarter-millennium, we decided to look back on how the country has demographically evolved since its last major milestone, the bicentennial.
One of the most striking developments since 1976 is the increasingly diverse face of the nation. As our Graphic Truth shows, Hispanic Americans have increased to roughly a fifth of the population – a more than fourfold jump – while the Asian American population has grown from under 1% in the 1970 census to 6% in 2024.
In 1970, only 4.7% of the US population was foreign-born, the lowest share in the country’s recorded history. That reflected the long shadow of the 1924 Immigration Act, which tightened immigration from everywhere other than the Western Hemisphere. That law, along with other restrictive immigration measures, wasn’t overturned until 1965. Because the US experienced relatively little immigration over the preceding four decades, the country’s demographic breakdown in the 1970s reflected a period of demographic stagnation.
Meanwhile, the share of non-Hispanic white Americans has dropped, from 83% to 56%. The near-30-percentage-point drop reflects a half-century of steady flows of immigration into the country, the growth of ethnic-minority groups, as well as an aging population and lower fertility rates, meaning deaths outnumber births among non-Hispanic white Americans.
There are data challenges when it comes to checking how America’s changing racial and ethnic makeup has changed. Since the 1970s, the way the US Census records race and ethnicity has changed. Only since 2000 has the census allowed Americans to tick off more than one box for race – prior to the 21st century, people of multi-racial backgrounds had to select the race with which they most identified.
In 2030, the census will change again. After decades of advocacy, people with origins in the Middle East and North Africa will receive their own ethnic category, and “Latino” will be included as an option under “race and ethnicity.” As the US approaches its 250th birthday, it’s clear the country remains a demographic in motion. The picture is always changing, and the next census suggests it will continue to evolve in ways that challenge assumptions about who Americans are.
