French public opinion pushed Napoleon III into attacking the Germans at Saarbrucken, which, while successful, did not have quite the same effect as the German advance on Wissembourg. While the German mobilization was more efficient, the large standing army of France could conduct offensive operations without waiting for their mobilization to be fully completed. That threat was a slight worry for Germany in their pre-war planning. Their worries were partially realized when they faced a reluctant French assault on Saarbrucken that comprised three French Corps against a single infantry regiment and a cavalry detachment.
The assault on Saarbrucken, spurred by the Emperor, who was aware of French public opinion, was a reluctant move by his Marshalls. They knew that the army of the Rhine was not yet prepared to conduct an all-out offensive. Many French troops were still trying to find their units, and much-needed supplies were not yet in position. However, Napoleon III insisted that an attack occur. Bazaine dedicated a part of his army to cross the border and take Saarbrucken, a victory that remained the only major French action on German territory. The French did not take advantage of their victory and instead spread themselves thin, reacting to often nonexistent threats while the German armies readied an attack of their own. The German First and Second armies began to move on the north, and the Third began to cross the frontier on the east, just thirty miles from Saarbrucken, near the town and railway hub of Wissembourg. The French army at Saarbrucken reacted by abandoning the town and returning to positions on French soil.
The Third German army crossed the border to take the town of Wissembourg, an important railway hub and a strategic position between the armies of Bazaine and Macmahon. Taking this town would prevent MacMahon or Bazaine from making the quickest transit through the Vosges and regrouping with the other army. Poor intelligence led to Wissembourg being defended by a single infantry division with a cavalry detachment under the command of General Abel Douay, with his superiors believing that the German forces in the area were not strong enough to take the town. As it turned out, the entire German third army was in the area, and they dispatched three Corps to take the town, with little chance for the rest of MacMahon’s spread-out army to react in time.
The battle of Wissembourg occurred on August 4th and was a quick and bloody victory for the Germans. It was fought in a single day and led to over 2300 dead, wounded, or captured for the French, including general Douay, who died during the fighting. The Germans suffered over 1500 casualties, many due to the French Chassepot rifle that outranged the German Dreyse rifle. During the battle, the French entrenched and defended the Geisburg hilltop chateau, forcing the Germans to advance uphill and under French fire just to get the French in range of the German Dreyse. This kind of event was a common bloody trend for the Germans in the coming battles and resulted in heavy losses among both the common rank-and-file and the officers trying to lead by example. The German forces continued their offensive and entered into two new major battles just two days after Wissembourg.
 Helmuth von Moltke; Harry Bell, Extracts from Moltke’s correspondence pertaining to the war 1870-71, Fort LeavenWörth, Kansas: Army Service School Press, 1911, P.114-115
 Moltke, The Franco-German War, P.4-5
 Pflugk-Harttung, The Franco-German War, P.67-71
 Moltke, Extracts, P.177-179
 Moltke, The Franco-German War, P.10-12
 Henry Montague Hozier; W.H. Davenport Adams, The Franco-Prussian War: Its Causes, Incidents, and Consequences, Volume 1, London: William Mackenzie, 1872, P.305-306
 General Staff School, Franco-German War, P.9-11
 Moltke, The Franco-German War, P.12-14
 Pflugk-Harttung, The Franco-German War, P.79
 Moltke, The Franco-German War, P.13
 Pflugk-Harttung, The Franco-German War, P.79-80