Returned to Algeria, the regiment was licensed on December 14, 1861, by Imperial decree. The men were accordingly transferred to the 2nd Foreign which changed name designation on January 1, 1862, to become the Foreign Regiment. During the Mexican expedition from 1861 to 1867, the foreign regiment embarked to Mexico where the latter arrived on March 25, 1863 at Veracruz. The 3rd combat company illustrated itself with distinction while sacrificing itself during the Battle of Camarón () on April 30, 1863. The 1st and 2nd battalions participated to the siege of Oaxaca which capitulated in April 1865. The 2nd battalion lost on March 1, 1866, 102 men killed during the combat of Santa Isabel. On December 13 of the same year, the regiment left Mexico. During the Franco-Prussian War (), the Legion engaged the conflict within delay. It was at the end of September 1870, that the regiment integrated the 15th Crops 1st Brigade, 2nd Division and was found making way towards Orléans (where the regiment refused 3 times consecutively the order to retreat and where foreign Lieutenant Kara, Peter I of Serbia illustrated capability) on October and December 1870 then at Montbéliard in January 1871, where he forced the Germans to leave the city.