What was the name of Thomas Edison’s first wife’s eldest child?

Thomas Edison’s eldest child was Marion Estelle Edison, commonly called Dot.

Marion was born in 1873 to Edison and his first wife, Mary Stilwell. She was the couple’s first child and was followed by Thomas Alva Edison Jr. and William Leslie Edison.

The nickname Dot reflected telegraphy, one of the technologies closely associated with Edison’s early career. In Morse code, a dot is one of the two basic signal elements, paired with a dash.

Marion later married Oscar Oeser. Her name is sometimes confused with that of Edison’s second wife, Mina Miller, but Marion was Edison’s daughter from his first marriage.