By the official estimate of the US Census Bureau, America's population crossed the 300 million mark on 17 October 2006. That day, although obviously bracketed by a generous error-term, was, unsurprisingly, occasion in the media for an outpouring of descriptions of the country's demographic path from the last similar benchmark 39 years earlier, when the US population reached 200 million. Projections for continued rapid population growth in the future were also matter-of-factly presented—an expected 400 million by 2043 with no stop in sight beyond that.

In the press, influential editorial opinion about the meaning and significance of the event was generally upbeat and self-congratulatory. The New York Times, for example, reminded its readers that “In America, growth and vitality are the same thing…. Our teeming immensity keeps us from growing stale.” Readers who might question that sentiment were reassured that “population issues have mysterious ways of working themselves out.”The Wall Street Journal's editorial page observed that the US population could comfortably be housed in the State of Texas (two acres for every US family of four), leaving the rest of the country deserted. On 17 October, the White House issued a presidential statement to “celebrate a significant milestone.” The closing sentences of its two short paragraphs convey the substance of its message: “Our continued growth is a testament to our country's dynamism and a reminder that America's greatest asset is our people.”“We welcome this milestone as further proof that the American Dream remains as bright and hopeful as ever.”

This celebratory welcome to the arrival of the 300 millionth American is in remarkable contrast to the somber national soul-searching that followed the crossing of the 200 million benchmark in 1967. In the context of the unprecedented pace of global population growth and reflecting the shock of the unanticipated US baby boom, the desirability of indefinitely sustained US population growth was then commonly viewed as far from obvious: certainly it was seen as an issue calling for careful examination and analysis. The demand for assessing the national interest in this matter was articulated and given a major impetus by a Message to Congress issued by then President Richard M. Nixon on 18 July 1969. The full text of this document is reprinted below. Drafted by the late Daniel Patrick Moynihan, then Counselor to the President (later US Senator from New York State), the message was primarily devoted to consideration of US population issues. It raised questions about the effects of the next 100 million Americans, expected “by the year 2000 or shortly thereafter,” on the economy and society. Those questions, it stressed, must be answered with a new sense of urgency. “Perhaps the most dangerous element in the present situation is the fact that so few people are examining these questions from the viewpoint of the whole society.” The message suggested that the Federal Government has “a special responsibility for defining these problems and for stimulating thoughtful responses.”

To assemble those responses, the President proposed the “creation by Congress of a Commission on Population Growth and the American Future.” In the following years the resulting Commission, chaired by John D. Rockefeller 3rd and with Charles F. Westoff of Princeton University serving as Executive Director of the Commission's staff, carried out a thorough examination of the issues surrounding US population growth. The seven hefty volumes in which its findings and supporting documents were published are quintessentially summarized in Rockefeller's letter of transmittal of the Commission's Final Report to the President and Congress of the United States on 27 March 1972: “After two years of concentrated effort, we have concluded that, in the long run, no substantial benefits will result from further growth of the Nation's population, rather that the gradual stabilization of our population through voluntary means would contribute significantly to the Nation's ability to solve its problems. We have looked for, and have not found, any convincing economic argument for continued population growth. The health of our country does not depend on it, nor does the vitality of business nor the welfare of the average person.” Notwithstanding the urgency accorded the matter in his message, Nixon ignored the recommendations of the Commission.