Complex sentence: After the war, he served in a succession of cavalry postings on the open frontier in the American Old West and traveled in Europe from 1859 until early 1861 on a leave of absence from the army.
Split into simpler sentences: After the war, he served in a succession of cavalry postings on the open frontier in the American Old West. Wood traveled in Europe from 1859 until early 1861 on a leave of absence from the army.