A Texas Rider and His Indian Motorcycle: This photo was taken in the Brenham area of Washington County, Texas, and dated 1918 by Winkelmann’s Studio.
Can you help date this machine? See it and 100s more @ http://theoldmotor.com/?cat=21
Looks like side valves, so it's a Powerplus, introduced in 1916. A system of nickel plated links from the left handlebar to the throttle instead of a cable, so it's an early Powerplus, maybe from the first year?
Note the US Flag whirley-bird on the front fender and the tire pump in front of the magneto.
yep, first year 1916