There don't appear to be any verifiably accurate population numbers. Our best guess is 60,000-65,000, leaning to the larger number. Of those, over 90% are Samoan. It is unclear how many Samoans are actually American Samoan, as many are immigrants from Samoa. The balance of the population is made up of white 1%, Asian 3%, mixed 4%, other 2%.
American Samoans are US Nationals. That means they have pretty much all the rights of US citizens minus the right to vote and to become president. Although they do need a passport, American Samoans can travel freely between American Samoa and the United States.
A major source of income to the territory is US Military Service. All branches of the military accept American Samoans and most have active recruiting offices in American Samoa. American Samoan members of the military earn far more than the average hourly employee in American Samoa. They often send money home to their families and family members are often able to receive dependant benefits from them. The Army Reserve Unit is very large and employs many American Samoans. But, there is a price to pay for all this benefit: American Samoans have the highest, per capita, death rate in the United States.
American Samoans are almost 100% literate and most complete high school. American Samoans are, in general, a very intelligent people. The public education system is among the poorest in the country (US) and high school graduates often lack simple math skills and have a poor level of basic understanding of the world around them. Private schools produce excellent results. There are many very well educated American Samoans that demonstrate extremely high levels of intelligence.
Samoans are typically just simply big people. On average, they are not exceedingly tall, but most have large bodies. Like most of the US, obesity is a major problem and American Samoans have a big problem with that. The World Health Organization and the CIA Factbook show American Samoans to be the most obese people on Earth. Childhood obesity is especially problematic.