The convey kept detailed statistics of the vehicles and roads encountered. The official report was compiled by William C. Greany, Captain Motor Transport Corps, United States Army Adjutant and Statistical Officer.
Below is a digitized version of the report. You can download the original report here:
Report, "Principal Facts Concerning the First Transcontinental Army Motor Transport Expedition, Washington to San Francisco, July 7 to September 6, 1919." [DDE's Records as President, President's Personal File, Box 967, 1075 Greany Maj. William C.; NAID #12005074]
Listen to Captain Greany's Voice
After Ike utilizes audio technology to recreate the voice of historic figures on the convoy. The voice you hear in certain segments of the film is not original archival audio, but an AI-representation as the voices of the individuals is unknown.
All content presented is based on factual historical records. We believe in transparency and want to ensure that our audience is informed about the methods used in the production of this documentary.
Captain Greany talks about his findings as a statistician of the trans-continental military convoy.
PRINCIPAL FACTS CONCERNING THE FIRST TRANSCONTINENTAL ARMY MOTOR TRANSPORT EXPEDITION, WASHINGTON TO SAN FRANCISCO JULY 7 TO SEPTEMBER 6, 1919
Briefed from the official report compiled by William C. Greany, Captain Motor Transport Corps, United States Army Adjutant and Statistical Officer.
Historical
The First Transcontinental Motor Convoy, conducted by the Motor Transport Corps of the United States Army, under the command of Colonel Charles W. McClure, inaugurated a new epoch in the long distance operation of heavy motor transport. In this connection, a world’s record was established in the total continuous distance traveled of 3,251 miles, the nearest approach to which was the record movement of an army motor convoy between Chicago and New York, through a distance of approximately nine hundred miles.

In addition to this record, the expedition possessed an historic significance, it being the first motor convoy to cross the American Continent, comparable in its sphere, to the first ox-team prairie-schooner trek; the first steam railroad train, and the first airplane flight across the vast expanses of fertile valleys, rolling prairie, rugged mountains, and desolate wilderness that lie between the Atlantic and Pacific Oceans.
After Ike utilizes audio technology to create the voice of Captain Greany in 1919.
Objectives
The principal objectives of the expedition were to service test the special-purpose vehicles developed for use in the first World War, not all of which were available in time for such use; and to determine by actual experience the possibility and the problems involved in moving an army across the continent, assuming that railroad facilities, bridges, tunnels, etc. had been damaged or destroyed by agents of an Asiatic enemy.

The expedition was assumed to be marching through enemy country and therefore had to be self-sustaining throughout, in addition to surmounting all of the obstacles interposed by mechanical difficulties, unfavorable road, bridge, topographical, and weather conditions. There were many and outstanding instances of the army Corps of Engineers motto in action: "To accomplish the purpose with the means at hand."
Personnel
The personnel consisted of 24 expeditionary officers, 15 War Department staff observation officers, and 258 enlisted men. Twenty-one men were lost thru various casualties en route.

West of Gothenburg, Nebraska, August 3, 1919. Ordnance built artillery tractor to the rescue.
Living Conditions
The living conditions of the personnel were comparable to those generally experienced in the advance zone of battle operations, but the tour of continuous duty was of a longer duration than is usual for such service.
The average amount of sleep which the personnel procured during the entire sixty- two days was limited, due to adverse conditions, to about five and one-half hours per day.

West of Gothenburg, Nebraska, August 3, 1919. Ordnance built artillery tractor to the rescue.
Aside from this, much inconvenience and at times even hardship was experienced due to the almost continuous and excessive amount of strenuous work, insufficient rest and sleep, lack of shelter, ration difficulties, lack of bathing facilities, and at times the scarcity of even drinking water.
Other conditions such as alternate extremes of temperature, rain, high winds, excessive dust, sand storms, and the rarefied and the extremely dry atmosphere of the arid western region combined to make a condition that only military discipline as administered by the commanding officer could overcome and insure the success of the expedition.
Schedule
The convoy proceeded on a pre-arranged schedule regardless of weather conditions. Heavy electrical, rain and windstorms were encountered on several occasions.
Winds were experienced for days at a time varying in velocity up to a maximum of 50 miles per hour in the Rocky Mountains in Wyoming, while absolute calm was met with on the Salt Lake Desert. Temperatures were observed which varied between a maximum of 110 degrees F. (130 in the sun) on the desert lands of Utah and Nevada and a minimum of 30 degrees in the Sierra Nevada Mountains.

This happens between Chambersburg, Pa. and Bedford, Pa, July 9, 1919. Climbing Tuscarora Mts in the Blue Ridge.
About 1,300 miles of the journey were traveled at altitudes between 4,000 and 8,000 feet while the highest point reached was 8,427 on the Continental Divide in Wyoming.
Progress
The convoy departed from the (temporary) Zero Milestone, on the Elipse south of the White House, in Washington, D. C., on the morning of July 7, 1919, and arrived at the Presidio in San Francisco, California, sixty-two days later, on September 6, after having accomplished an average progress of 58.1 miles per day and 6.07 miles per hour of running time, much of official Washington, under the leadership of Secretary of War Baker and Army Chief of Staff March, were present at the starting ceremony. A granite and bronze milestone now marks the starting point of this historic expedition.

Vehicles
A total of 79 specialized military vehicles were included in the convoy, with individual gross weights ranging up to a maximum of 22,45O pounds.
The convoy was comprised of 34 heavy cargo trucks, 4 light delivery trucks, 2 machine shops, 1 blacksmith shop, 1 wrecking truck, 2 spare parts stores, 2 water tanks, 1 gasoline tank, 1 searchlight, 1 caterpillar tractor, 4 kitchen trailers, 8 touring cars, 1 reconnaissance car, 2 staff observation cars, 5 sidecar motorcycles, and 4 solo motorcycles.

Near Pulton, Illinois, July 22, 1919. Riker truck of the 5th Engineers turned turtle and was righted with block and tackle.
Of these, 9 vehicles were destroyed or so damaged as to require retirement while en route.
Roads
In 1919, there were no transcontinental highways. The route directed for the convoy was the proposed location of the Lincoln Highway (now US-30) which at that time existed largely in the imagination and on paper.
Of the entire distance traversed, 1,778 miles or 54.7 per cent of the mileage was made over dirt roads, wheel paths, mountain trails, desert sands and alkali flats. Of this distance, over 500 miles was practically impassible to the heavy vehicles which were included in the convoy, and was negotiated only through the combined efforts of the most extraordinary character on the part of the personnel.

West of North Platte, Nebraska, August 5, 1919. Quicksand.
It frequently was necessary to pull and push the vehicles by man-power over wide areas of gumbo mud in the central states and across the desert lands of the far west, for many hours at a time, and to laboriously construct wheel paths of timber, canvas, sage brush or grass for long distances.
On a number of days the personnel labored from fifteen to twenty-four hours to accomplish the pre-arranged forced-march itinerary.

West of North Platte, Nebraska, August 5, 1919. Quicksand. Closeup of the apparatus used in endeavoring to move the truck.
There were also encountered hundreds of miles of mountain trails some of the most dangerous character with steep grades, and numerous sharp turns, where a deviation from the wheel paths meant destruction in the depths below.
On the alkali flats dust up to 2 feet in depth was passed through, while in other localities quicksands were encountered in which certain of the trucks sank to depths up to several feet and had to be rescued by timber, rope and chain tackle and jacks.
Road Accidents
There were 230 road accidents, that is, instances of road failure and vehicles sinking in quicksand or mud, running off the road or over embankments, overturning, or other mishaps due entirely to the unfavorable and at times appalling traffic conditions that were encountered.

Near Pulton, Illinois, July 22, 1919. Riker truck of the 5th Engineers turned turtle and was righted with block and tackle.
In addition to this, there were three instances involving an aggregate period of forty-two hours, which were spent in the most arduous and heroic effort in rescuing the entire convoy from impending disaster on the quicksands of the Salt Lake Desert in Utah and the Fallow Sink Region in Nevada.
In these emergencies, the entire personnel, regardless of rank, engaged in rescue and salvage operations.
Bridges
During the progress of the convoy, there were damaged or destroyed a total of eighty-eight mostly wooden highway bridges and culverts, all of which had to be repaired or rebuilt by the convoy personnel, before the expedition could proceed.

Rest of convoy detoured around bridge driving down through the creek bottom with the aid of the portable corduroy road.
It was practically impossible to determine the stability of a bridge thru pre-inspection, due to the dried-out condition of its timbers. Even some of the bridges reinforced by the convoy engineers collapsed during use.
Public Relations
The expedition crossed eleven states in addition to the District of Columbia, and passed through about 350 communities. In this way, approximately 3,250,000 persons were afforded an opportunity to personally see a unit of a motorized army and to understand the vast importance and urgent necessity of motor transport and good roads in the cause of national defense.

It is estimated that this matter brought directly to the attention of about 33,000,000 persons, or nearly one-third of the population of the entire country through the medium of local publicity in the states crossed. In a number of communities, refreshments were served to the personnel.
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Unless indicated otherwise, all images are screenshots from the silent movie filmed by the army in 1919.