Bendix was born in between the United States and Canada, on board the "Sarah," one of the first steamers that navigated St. Lawrence River.

While yet in his teens, young Bendix returned to the U.S. and settled in New York City, where he learned the trades of pattern maker and machinist.

[1] Following the outbreak of the American Civil War in 1861, Bendix organized the 7th New York Infantry and was appointed as its first colonel on April 23, 1861.

Bendix was carried from the battlefield at Fredericksburg after suffering a serious wound in the neck from a shell fragment during the assault on Confederate entrenchments on Marye's Heights.

He rejoined his regiment in January 1863, and assumed command of the 3rd Brigade, 3rd Division of the II Corps between March 16, 1863 and April 27, 1863.