American Operations in the St. Mihiel Region

Overview of the St. Mihiel Offensive

• Date: Began on September 12, 1918
• Significance: First major operation by a complete American army under independent American command.
• Objective: Reduction of the St. Mihiel salient to pave the way for further operations.
• American Commander: General Pershing.
• Collaboration: Agreed upon by General Pershing and French General Ptain.

Strategic Importance of St. Mihiel

• Geography: Salient was a triangular wedge into Allied lines.
• Defensive Strength: Fortified with trenches, barbed wire, and strongholds like Montsec.
• German Objectives: Protect Metz and Briey iron basin, disrupt Allied rail communications.

Pre-Offensive Preparations

• Formation of American First Army: Started functioning on August 10, 1918.
• Troop Concentration: Began assembling units near St. Mihiel in late August.
• Allied Concerns: French and British preferred some American units remain integrated with their forces.

Execution of the Offensive

• Plan: Main attack against the southern face, secondary attack against the western face, holding actions at the tip.
• Corps Involved: I, IV, and V Corps; French II Colonial Corps.
• American Divisions: Included the 1st, 2nd, 26th, 42nd, 78th, 82nd, 89th, and 90th Divisions among others.
• Scale of Operation: Over 550,000 American and 110,000 French troops involved.

Battle Progression

• Initial Assault: Began at 5:00 AM on September 12 under heavy artillery cover.
• Advancement: Rapid gains with minimal resistance due to surprise and intensity.
• Key Developments: Closing of the salient by nightfall of September 13.
• Further Operations: Continued local attacks and consolidations until September 16.

Outcome and Impact

• Success: Entire salient reduced, freeing up a large area for Allied use.
• Casualties and Gains: Less than 9,000 American casualties; over 15,000 prisoners captured.
• Strategic Advantage: Cleared a path towards Briey-Metz region.
• Psychological Impact: Boosted Allied morale and demonstrated American military competence.

Post-Operation Developments

• Subsequent Movements: Transfer of divisions to the Meuse-Argonne region.
• Ongoing Operations: American Second Army took over parts of the line in October.

Key Locations and Divisional Actions

• Montsec: Important observation point and defensive position.
• Thiaucourt and Nonsard: Captured as part of the main attack.
• Vigneulles and Hattonchatel: Key positions in closing the salient.

Legacy

• Memorials and Cemeteries: St. Mihiel American Cemetery and Montsec Memorial commemorate the operation and its sacrifices.
• Historical Tours: Suggested routes cover significant battle sites and memorials in the region.