The first photographic portraits were taken in 1839, but it took decades for the custom to become common. This is a portrait of Conrad Heyer, taken around 1852. Heyer may be earliest-born person ever photographed, as he was born in 1749!
He was approximately 103 when photographed, having been born in 1749. He was reportedly the first white child born in Waldoboro, Maine, then a German immigrant community. He served in the Continental Army under George Washington during the Revolutionary War, crossing the Delaware with him and fighting in other major battles. He eventually bought a farm and retired to Waldoboro, where he happily regaled visitors with tales of his Revolutionary War exploits until his dying day.
The article at Doug's Darkworld goes on to describe how different the world was at the beginning of Heyer's life from the modern world in which he had his portrait made. Link -via reddit