LOS ANGELES -- It was early yesterday morning at White Memorial Medical Center in Boyle Heights, and Gloria Mejia was reminding her 18-year-old daughter, Catalina Meza, that she had a chance to make history.
If Meza could just push a little harder, her mother told her, the little girl she was about to give birth to had a shot at being the so-called 300 millionth American.
"Andale apurate" - come on, hurry up, Mejia said excitedly in Spanish. "Your baby could be the one!"
Baby Anareli entered the world at 5:10 a.m. - 24 minutes after the moment the U.S. Census bureau had estimated the United States population would reach 300 million.
"We won!" patients and nurses at White Memorial shouted.
Employing a complex and highly subjective set of calculations, the Census bureau had set Oct. 17 at 4:46 a.m. Pacific time as the moment the country would cross the milestone.
But census officials stressed yesterday that the date and time are just guesses. Some demographers believe the U.S. hit the number months ago, more likely from someone crossing the border than from a birth in a maternity ward.
The Census Bureau office in Washington marked the moment in a low-key manner with cake and punch.
Back in 1967, Life magazine spent months researching who was America's 200 millionth person before settling on Robert Ken Woo Jr., who was born in an Atlanta hospital.
This time around, the census bureau said it had no plans to designate a 300 millionth American and seemed to go out of its way to dampen speculation.
But that didn't stop folks at White Memorial and beyond from celebrating.
In New York City, officials at Queens' Elmhurst Hospital officials proclaimed Emmanuel Plata number 300,000,000 - claiming she was born precisely at 7:46 a.m. Eastern time by cesarean section. Beforehand, the hospital had T-shirts and blankets made for the baby and mother with "300 millionth American Baby" printed on them.
"We were anticipating this," said Chris Constantino, the executive director of Elmhurst. "It's not like a census official came and put a sticker on the baby. We just took the opportunity. We stake our claim to it, but anyone else can too. This is not staged."
A few hours after the New York press descended on the Queens medical center, New York Presbyterian Hospital announced that its doctors had delivered a baby girl at exactly 7:46 a.m.
But Elmhurst - which won a New York commendation for birthing the first baby on New Year's day four of the past seven years - wasn't backing down.
"What better place than New York City?" Constantino said.
The folks at White Memorial would have an answer to that.
The medical staff has been following the news coverage about the 300 millionth American for several days. They were particularly intrigued by speculation from demographers that the person would be an immigrant - because they serve a neighborhood with a large population from Mexico.
The estimated time of arrival is determined by the rate of growth of the U.S. population. According to the Census Bureau, there is one birth in the United States every seven seconds and one death every 13 seconds. The population grows by one international immigrant every 31 seconds. Doing the math means that the population grows by one person every 11 seconds.
The population of the United States hit 100 million in 1915. It took another 52 years to hit 200 million and just 39 more years to hit 300 million, so the rate of growth has accelerated. That trend seems to have slowed a touch, so the 400 millionth American may not arrive until around 2050.
President Bush marked the occasion with a statement saying its "further proof that the American Dream remains as bright and hopeful as ever."
Catalina Meza and her husband Alvaro, 21, did not give the number much thought to any of this when they stopped at a clinic across from the hospital Monday afternoon.
Catalina said she expected to go home after a checkup, only to find out that she was four centimeters dilated. She was checked into White Memorial Medical Center.
It was her mother who urged her to press on and deliver her baby, excited about the news coverage.
"My mother told me to hurry. But the truth is, it didn't really matter to me," Catalina Meza said as she nuzzled her baby against her cheek. "I just wanted my baby to be born healthy."
Hector Becerra and David Pierson write for the Los Angeles Times.