High Quality Content by WIKIPEDIA articles! The Actions along the Matanikau in September and October 1942—sometimes referred to as the Second and Third Battles of the Matanikau—were two separate but related engagements among a series of engagements between the United States and Imperial Japanese naval and ground forces around the Matanikau River on Guadalcanal during the Guadalcanal campaign. These particular engagements—the first taking place between 23 and 27 September, and the second between 6 and 9 October—were two of the largest and most significant of the Matanikau actions.