Were the American soldiers well received by Entente forces? How much trench warfare did they participate in?
The large-scale, hopeless, "charging into machine guns to their deaths" sort of attacks were largely a phenomenon of 1914-1916. By early 1916, this had given way in the French Army to coherent small-unit tactics (previously, units had attacked in battalion-sized instead of company or squad-sized formations) using numbers of easily portable weapons, developed by pioneering officers such as André Laffargue. The Germans and British also began to use such tactics. More modern inventions such as the airplane, the man-portable light machine gun or automatic rifle, and the tank (used by the British, but also by the French and a lesser extent the Germans) were also put to use; World War I saw the first use of tactical bombing (hitting targets of immediate military value) and artillery spotting via airplane (stationary balloons were also used for spotting) As u/batmanintexas noted, the American army was wholly unprepared for World War I. The concept of permanent divisions was a new one to the Americans, and they reorganized them several times. Previously, such as in the American Civil War, divisions were only an administrative formation, midway between the regiment and corps.
African-American soldiers, even though they received poor treatment at home, were welcomed by the French. The 92nd and 93rd Infantry Divisions were colored units of the National Army (draftee force) The 92nd Infantry Division fought as a whole, but the 93rd Infantry Division was split up and attached around to bolster various French divisions. Both units used large amounts of French equipment, (more so than other U.S. units) including helmets and rifles, and were highly decorated by French military authorities.
Initially, American divisions were organized as follows;
A headquarters,
Two infantry brigades,
Each containing two regiments, each with three battalions, each of three rifle companies and one machine gun company
A three-company machine gun battalion organic to each infantry brigade
A field artillery brigade (two 3-inch or 4.7-inch gun regiments, one 6-inch howitzer regiment),
An engineer regiment,
A five-company divisional machine gun battalion, with an armored car unit
A signal battalion,
Division supply and sanitary trains
Before American entry into World War I, the General Organization Project altered the divisional structure to better reflect combat conditions learned from observations in Europe, foreseeing a type of division that was actually less mobile than envisioned because the front lines were not moving as expected. The armored car section of the divisional machine gun battalion was eliminated. One-pounder (37 mm) infantry guns (a French piece designated the 37mm M1916) were added to the infantry regiment as antitank and anti-fortification weapons, and 3-inch British trench mortars were made available. The divisional artillery switched to using French 75 mm and 155 mm pieces, as U.S.-built guns of the time were unsatisfactory and too few in number. The divisional machine gun battalion was reduced to four companies, and later motorized and reduced to two companies;
A headquarters,
Two infantry brigades,
Each containing two regiments, each with three battalions, each of four rifle companies
A three-company machine gun battalion organic to each infantry brigade
A field artillery brigade (two 75 mm gun regiments, one 155 mm howitzer regiment),
An engineer regiment,
A two-company motorized divisional machine gun battalion,
A signal battalion,
Division supply and sanitary trains
The U.S. Army numbered their divisions as follows. Originally 1 to 25 were reserved for divisions of the Regular Army, 26 to 75 for divisions of the National Guard, and 76 and above for the National Army. It was intended that mounted cavalry divisions were to utilize the numbers from 15 to 25. Blocks of numbers of infantry and cavalry brigades were also reserved; 1 through 50 for the regular army, 51 through 150 to the National Guard, and 150 and above for the National Army. The National Army of World War I was organized in a unique manner, with draftees coming from specific states. This process would not be repeated in World War II for those divisions comprised primarily of draftees. Many U.S. divisions earned their nicknames based upon World War I-era particulars; the 77th Infantry Division, as it came from New York City, was given the nickname "Statue of Liberty." The 86th Infantry Division from Illinois was given the nickname "Black Hawk" after the famous Native American leader who spent portions of his life in Illinois. The previously proposed National Guard divisions were renumbered under this new numbering system.
| Division | Component | Recruiting Area |
|---|---|---|
| 1st | Regular Army | -- |
| 2nd | Regular Army | -- |
| 3rd | Regular Army | -- |
| 4th | Regular Army | -- |
| 5th | Regular Army | -- |
| 6th | Regular Army | -- |
| 7th | Regular Army | -- |
| 8th | Regular Army | -- |
| 26th (old 5th) | National Guard | ME, NH, VT, RI, CT |
| 27th (old 6th) | National Guard | NY |
| 28th (old 7th) | National Guard | PA |
| 29th (old 8th) | National Guard | NJ, VA, MD, DE, Washington, D.C. |
| 30th (old 9th) | National Guard | TN, NC, SC |
| 31st (old 10th) | National Guard | GA, AL, FL |
| 32nd (old 11th) | National Guard | MI, WI |
| 33rd (old 12th) | National Guard | IL |
| 34th (old 13th) | National Guard | MN, IA, NE, ND, SD |
| 35th (old 14th) | National Guard | MO, KS |
| 36th (old 15th) | National Guard | TX, OK |
| 37th (old 16th) | National Guard | OH, WV |
| 38th (old 17th) | National Guard | IN, KY |
| 39th (old 18th) | National Guard | LA, MI, AE |
| 40th (old 19th) | National Guard | CA, NV, UT, CO, AZ, NM |
| 41st (old 20th) | National Guard | WA, OR, MT, WY |
| 42nd | National Guard | Handpicked National Guard units from 26 states and the District of Columbia |
| 76th | National Army | ME, NH, VT, RI, CT |
| 77th | National Army | Metropolitan New York City, NY |
| 78th | National Army | NY, northern PA |
| 79th | National Army | Southern PA |
| 80th | National Army | NJ, VA, MD, DE, Washington, D.C. |
| 81st | National Army | TN, NC, SC |
| 82nd | National Army | GA, AL, FL |
| 83rd | National Army | OH, WV |
| 84th | National Army | IN, KY |
| 85th | National Army | MI, WI |
| 86th | National Army | IL |
| 87th | National Army | AR, LA, MS |
| 88th | National Army | MN, IA, NE, ND, SD |
| 89th | National Army | MO, KS, CO |
| 90th | National Army | TX, OK, AZ, NM |
| 91st | National Army | WA, OR, CA, NV, UT, ID, MT, WY |
| 92nd | National Army | Colored draftees from all over the United States |
| 93rd | National Army | Various colored units from CT, Washington, D.C., IL, MD, MA, NY, OH, TN |
The Evolution of British Infantry Tactics in World War One, by Roger Daene
U.S. Order of Battle in World War I
Basic Fighting Unit of the A.E.F.: The Square Division
The Evolution of Divisions and Separate Brigades (The Test: World War I), by John B. Wilson
Shortly after the war began, the French and British cut the transatlantic connections between Germany and the United States. This meant that dispatches coming from American reporters in Germany and traveling with German forces could not get their dispatches out easily. It also allowed the French and British to censor American reports from the front. The British were particularly keen to get the United States into the war and were cautious about what they let on to the American public. The biggest example of this having an effect on the AEF (American Expeditionary Force) when it sailed to France was in Chemical Warfare.
Following the German chemical attacks in April 1915 that began the Second Battle of Ypres (incidentally not the first use of chemical weapons in World War I, but I digress), the British and French were quick to turn the attack into a propaganda event as part of a broader "atrocity" propaganda effort. After that however, as both the French and British started using chemical weapons, reports of those uses disappeared from American media. This (along with Wilson's official policy preventing the Army from preparing for war between 1914-1917) meant that when the first American forces sailed to Europe, they had no gas masks or chemical defense training or equipment. None.
In fact, the American military was singularly unprepared for war in Europe in every aspect. That is why the token forces sent in 1917 (the 1st Division, followed later by elements of the 2nd) spent the next 6 months training and scrounging equipment from the French and British before deploying into the front.
That said, the "mud and blood" of the trenches was a phenomenon of 1915-1917. The German Spring Offensives in 1918 returned a semblance of "open warfare" to the western front involving maneuver and defense in depth tactics - as well as widespread chemical weapons use especially of mustard (a new agent). The war in 1918 (the only year in which American forces saw combat) was fundamentally fought differently than the previous years of the war - by all combatants. Each adapted and adopted tactics from the Germans that were originally perfected on the Eastern Front against Russia (the so-called Hutier tactics which tend to be remembered for the introduction of stormtroopers, but were actually more about the tactics of Georg Bruchmuller - nicknamed "Durchmuller" which translates roughly as "breakthrough" Muller). Bruchmuller's artillery tactics made heavy use of chemical weaponry and new artillery attacks to disrupt enemy counter-battery fire and counter-attacks, and led to the return of open warfare on the western front beginning with the Spring Offensives.
As for the AEF's welcome, both the French and British forces were completely exhausted by the end of 1917. As their grand offensives (especially the British in Passchendaele) ground to a bloody halt, both needed to completely rebuild their armies. Several units experienced mutinies by troops disgusted with their treatment and the ineptitude of their commanders. The American entry into the war was a massive moral boost for the French and British. That became militarily significant when several units of the AEF (under French and British higher command) participated in critical battles during the German Spring Offensives - especially at Chateau-Thierry/Belleau Wood. Further, the German Spring Offensives were launched in part because the German High Command (Luddendorff and Hindenberg) knew that they needed to go for broke and try and end the war before significant American forces could be brought to bear.
For reference see - David Zabecki, Steel Wind (Prager 1994) and The German 1918 Offensives (Routledge, 2010). See Charles E. Heller, Chemical Warfare in World War I: The American Experience 1917-1918 (US Army Command and General Staff College, 1984); Winston Churchill, The World Crisis, vol. 3 (various reprints); and Paul Braim, The Test of Battle: The American Expeditionary Forces in the Meuse Argonne (1st Edition 1987 2nd Edition 1998) - note the two editions are vastly different books.