Who played Lucas McCain in the American Western television program, "The Rifleman", in the 1950's/1960's?

The Rifleman is an American Western television program starring Chuck Connors as rancher Lucas McCain. It was set in the 1870s and 1880s in the town of North Fork, New Mexico Territory. The show was filmed in black-and-white, half-hour episodes. The Rifleman aired on ABC from September 30, 1958, to April 8, 1963, as a production of Four Star Television. It was one of the first prime time series on American television to show a widowed parent raising a child.

The program was titled to reflect McCain's use of a modified Winchester rifle. Shown at the beginning of every episode in the opening credits, McCain would fire the rifle using the lever rather than pulling the trigger.