The population of the United States reached the historic milestone of 300 million today at about 7:46 a.m. This comes almost 39 years after the 200 million mark was reached on Nov. 20, 1967 and 91 years after the 100 million mark in 1915. Despite the recent dramatic growth, it took 125 years -- more than half of U.S. History -- to reach that 100 million mark.

The population estimate is based on the expectation that the United States registers one birth every seven seconds and one death every 13 seconds, while net international migration adds one person approximately every 31 seconds. The result is an increase in the total population of one person every 11 seconds.

America has grown and changed during these past 91 years in many ways beyond a tripling of the nation's population. I find it especially interesting that the price of gas and milk have actually decreased dramatically when adjusted for inflation.

1915:

Price of a new home: $3,200 ($64,158 in 2006 dollars)
Cost for a gallon of regular gas: 25 cents ($5.01 in 2006 dollars)
Price of milk: $ .36 gallon ($7.22 in 2006 dollars)
Cost of a first-class stamp: 2 cents
World population: 1.8 billion
Notable events: World War I continues in Europe
Pop Culture: The Model T and silent movies are the rage. Raggedy Ann, aspirin in tablet form and processed cheese are introduced. The milk carton is invented.

1967:

Price of a new home: $24,600 ($149,147 in 2006 dollars)
Cost for a gallon of regular gas: 25 cents ($5.01 in 2006 dollars)
Price of milk: $1.03 gallon ($6.24 in 2006 dollars)
Cost of a first-class stamp: 5 cents
World population: 3.5 billion
Notable events: Dr. Christiaan Bernard performs the first heart transplant; the first Super Bowl is played.
Pop Culture: Color TV is the rage. “The Lucy Show,” “Andy Griffith” and “Gomer Pyle” are the top-rated television shows.

2006:

Price of a new home: $290,600
Cost for a gallon of regular gas: $2.23 (as of October 16)
Price of milk: $3.00 gallon
Cost of a first-class stamp: 39 cents
World population: 6.5 billion
Notable events: The 20th Winter Olympic Games take place in Turin, Italy.
Pop culture: iPods and "American Idol" reign supreme and cell phones are the rage.

There are no plans to attempt to identify the 300 millionth individual as calculating exact times of birth and death and tracking immigrants, both legal and illegal would be close to impossible. Especially since the 300 million mark is just an estimate in itself. Demographers predict, however, that the lucky individual will be a baby boy of Latino heritage born in Los Angeles. This prediction is based on the fact that about half of the U.S. population growth is due to Hispanics, the biggest gains in the Hispanic population are in Los Angeles, more boys are born than girls, and the U.S. population is growing more due to natural increase than through immigration.

In Atlanta, lawyer Robert Ken Woo Jr., lauded as the 200-millionth American, is happy to pass the torch. He was born to Mr. & Mrs. Robert Woo in Atlanta, Georgia, at 11:03 a.m. on November 20, 1967, the moment the Census Clock in Washington hit 200 million.

_{Source: U.S. Census Bureau}

Related:
Researching Ancestry in the U.S. Census
Population Geography
U.S. Foreign Born Population Hits 33 Million
100 Most Common U.S. Surnames & Their Meanings