The regiment was re-formed in 1840 and took part in suppressing the June Days in Paris from 23 to 26 June 1848. It was renumbered as the 99th Infantry Regiment in 1855 and soon afterwards took part in the conquest of Algeria from 1855 to 1859. It formed part of 5th Corps during the 1859 Italian campaign but saw no actual fighting. Next it was put on garrison duties in Saint-Malo, Laval and Saint-Brieuc before being sent as part of the French intervention in Mexico, taking part in the siege of Puebla and the battle of Aculcingo and winning the légion d’honneur at the latter. It returned to garrison duties in Vienne and was still there on the outbreak on the Franco-Prussian War in 1870 – it fought at on 6 August and in September, whilst three of its companies were used to form the 44th Marching Regiment, which fought at Chilleurs, Ladon, Boiscommun, Neuville-aux-Bois and Maizières in the Loiret.