The US population is on target to hit 300 million this fall and it's a good bet the milestone baby, or immigrant, will be Hispanic. No one will know for sure because the date and time will be just an estimate. But Latinos, immigrants and those born in the US, are driving the population growth. They accounted for almost half the increase last year, more than any other ethnic or racial group. White non-Hispanics, who make up about two-thirds of the population, accounted for less than one-fifth of the increase. When the population reached 200 million in 1967, there was no accurate tally of US Hispanics. The first effort to count Hispanics came in the 1970 census, and the results were dubious. The Census Bureau counted about 9.6 million Latinos, a little less than 5 percent of the population. The bureau acknowledged that the figure was inflated in the Midwest and South because some people who checked the box saying they were "Central or South American" thought that designation meant they were from the central or southern United States. There are 36 million immigrants in the US, about one in eight.