|San Francisco Chronicle, June 19, 1903|
Spanish rule over Guam effectively ended on June 21, 1898 when Spanish Governor Marina, and all the other Spanish officers and troops, were put on board American ships and taken to Manila. The American flag now flew over Guam.
Many babies were born on Guam for the rest of the year 1898. Many more were born in 1899, 1900 all the way up to 1903. But none of them were American.
No, the first American baby born on Guam didn't appear until March 23, 1903. It was a baby girl, the daughter of Lieutenant and Mrs. Eugene Ryan of the US Navy, occupying the position of island paymaster.
Why weren't all those babies born in 1900 and 1902 with names like Pérez and Taitano and Borja and Sablan considered American babies? Because the Chamorros of Guam just happened to be living on an island owned by the United States, but not an integral part of the United States. United States citizenship wouldn't be granted until 1950 and, even now, Guam remains an unincorporated territory of the United States. Unincorporated. Not an integral part of the United States.
The little girl, names Eugenia Louise Elizabeth Ryan, happened to have Catholic parents and she was baptized at the Hagåtña Church (it wasn't a cathedral yet) on Easter Sunday, with none other than the American Governor, William Sewell, taking the part of godfather while the godmother was the wife of a Navy doctor.
Her birth was hailed as a historic event, not only by the military community but also by some of the Chamorro upper class who gave their share of christening gifts to the infant.
Guam was constantly being visited by American whaling ships (and those of other countries as well). Although it wasn't often that women were on board, it did happen at times that whaling captains had their wives along. We cannot rule out the possibility that an American couple came to Guam just as the wife was about to give birth and did give birth to an American baby on Guam during Spanish times. We do know of one case where a British mother, married to a British man, gave birth to a girl either on Guam or on the high seas heading towards Guam during Spanish times.