Unknown Inhabitant, 1842
The earliest mention of Palmyra's inhabitants comes from the 23rd volume of Charles Wilkes' account of the US Exploring Expedeition, where he says:
This island is inhabited, and is situated in latitude 5° 50' north, and longitude 162° 23' west...It is to be regretted that all these detached islands should not be visited by our national vessels, and friendly intercourse kept up with them. The benefit and assistance that any shipwrecked mariners might derive from their rude inhabitants, would repay the time, trouble, and expense such visits would occasion.
While little specifics are offered in this account, we can assume by "inhabited", Wilkes meant with native islanders. It's likely, especially given what later sailors would learn of the people on nearby islands like Fanning and Christmas, that these were only visitors, much like the crew of the Porpoise, but not permanent residents. The earliest accounts of Palmyra's discovery mention nothing of inhabitants either, and those visitors found no evidence of structures or habitation.
While perhaps a good place to visit for fish, wood, and other resources, native Pacific peoples never seem to have found it worth living on.