Campbell served with a battalion of the Sixtieth in Nova Scotia from October, 1814, to July, 1815, when ill-health caused by his wounds compelled him to return to Europe. After a course of thermal treatment in southern France he served for two years at Gibraltar, and early in 1819 followed to Barbadoes the Twenty-First Fusiliers to which regiment he had been transferred. The next seven years of his life he passed in the West Indies,--the first two years of the seven in Barbadoes, the latter five in Demerara, where he served as aide-de-camp and brigade-major to the Governor, General Murray. The tropical climate of the West Indies agreed with him, and notwithstanding recrudescences of Walcheren fever and frequent annoyances from his wounds he was able to enjoy life and relish the society of the colony. During his soldiering in Spain he and his friend and comrade Seward had perforce lived on their pay, and had firmly avoided incurring debt. With his captain's pay and his wound-pension Campbell found himself no longer obliged to live penuriously, and indeed was able to assist his father by a considerable annual payment. And now in Demerara with his staff-appointment he was so well off that, in his disregard for money, he carelessly allowed his pension to lapse, a neglect which he had bitter reason to regret later. His friend General Murray was succeeded in the Demerara command by General Sir Benjamin D'Urban, a distinguished Peninsular officer, between whom and his brigade-major there was speedily engendered a mutual esteem and affection. Probably, indeed, those years in Demerara were the pleasantest of Colin Campbell's life. Comfortable (and we may be sure efficient) in his staff-position, and the right hand man of a chief who loved him, he was happy in his regiment and welcome everywhere in society. When in November, 1825, the opportunity presented itself for his promotion by purchase to a majority in his regiment, it was the spontaneous generosity of a colonial friend which mainly enabled him to buy the step. The promotion was of the greatest professional importance to him, and indeed may be considered the turning-point of his career; but it required him to vacate his pleasant appointment and to take leave of the chief whose friendship he so warmly cherished. Returning to England in 1826 to join the depôt of his regiment, he took home with him the strongest recommendations from Sir Benjamin D'Urban to the authorities at the Horse Guards; but he continued to serve with his regiment at home until the autumn of 1832 in the rank of major, although through the kindness of a relative the money was ready for the purchase of his promotion to the rank of lieutenant-colonel.