[1] At the age of sixteen, Hendrick joined the rodman engineer corps on the Chesapeake, Ohio and Southwestern Railroad.

Hendrick was appointed assistant to the chief engineer of the Georgia Southern and Florida Railway and worked on the construction of the line from 1886 to 1887.

[1][2] While in Macon, Hendrick was appointed receiver of the Savannah and Western Railroad by Judge Emery Spear.

[3] Hendrick was selected by William Barclay Parsons, the engineer-in-chief of the New York City Subway, to assist in making surveys and sewer studies.

[3] Hendrick, at one point, declined the opportunity to construct the US$10,000,000 sewage system in Havana, Cuba.

[3] On November 4, 1905, Hendrick was elected unanimously as chief engineer for the construction of the Baltimore sewage system.

Mayor E. Clay Timanus appointed Hendrick a member of the commission to plan the facility.

His combined salary was US$14,000 a year, the highest paid city official in Baltimore at that time.

[12] Hendrick's name is on a bronze tablet in the New York City Hall subway station commemorating his work.