Hard to know who these people are, but the third person from the left appears to be General Black Jack Pershing (notice the stars on sleeve if you enlarge).
The Model T here has a different halftrack setup than I have seen before, with four tires on a side rather than the more customary three. This was called the Chase Track System.
The tank behind the Model T halftrack is a Mark VIII - a joint UK and US main battle tank for the 1919 western front offensive, which never occurred since Germany collapsed in November of 1918. After the World War I, 100 of these Mark VIII tanks were assembled in the US and used by the Army until they were mothballed in 1932. At the start of World War II, the tanks were given to Canada for training purposes.