In spring 1864 Union armies under William Tecumseh Sherman advanced from Chattanooga toward Atlanta, an industrial and railroad center vital to the Confederacy. Confederate general Joseph E. Johnston repeatedly occupied defensive positions and withdrew when threatened on the flank. By June heavy rain, mud, exhausted troops, and strong earthworks slowed movement around Kennesaw Mountain. The landscape held farms, roads, enslaved people, free residents, churches, fields, and wooded ridges before armies converted it into a fortified zone. Civilian displacement and destruction accompanied military maneuver.

Johnston's troops entrenched along Kennesaw Mountain, Little Kennesaw, Pigeon Hill, and Cheatham Hill. On 27 June Sherman ordered direct assaults intended to break the line and test whether Johnston had stretched his defenses. Union attacks at Pigeon Hill and Cheatham Hill encountered abatis, rifle pits, artillery, steep ground, and concentrated fire. They failed with heavy casualties. The battle was larger than the single famous assault and formed part of weeks of skirmishing, artillery exchanges, entrenchment, supply activity, and maneuver across a broad front.

Sherman soon resumed flanking movement, forcing Johnston to abandon the Kennesaw line on 2–3 July. Union forces crossed the Chattahoochee and captured Atlanta in September, strengthening Abraham Lincoln's prospects for reelection and damaging Confederate logistics. Soldiers later remembered Kennesaw through regimental histories, reunions, monuments, and veteran narratives. Lost Cause interpretation often separated battlefield courage from slavery, the institution the Confederacy fought to preserve. Enslaved and newly freed African Americans experienced occupation, labor demands, flight, and uncertain emancipation around the campaign, although their physical traces are less monumental.

Congress first protected portions of the battlefield in 1917, and the area became a national battlefield park in 1935. Civilian Conservation Corps crews developed roads, trails, landscaping, and facilities. Later suburban growth around metropolitan Atlanta isolated the protected landscape and increased traffic and recreation pressure. The park preserves extensive Confederate and Union earthworks, gun positions, road traces, and archaeological sites. Trees have regrown on areas that were more open in 1864, and monuments and interpretive structures postdate the battle. The terrain is conserved, not reconstructed to one wartime appearance.

The National Park Service manages Kennesaw Mountain National Battlefield Park for history, natural resources, and heavily used hiking and recreation. Grounds and trails are generally free, while parking systems, shuttle operations, road access, and visitor-center hours may vary. Visitors must avoid walking on vulnerable earthworks or removing artifacts. The park's strongest interpretation connects tactical events to the Atlanta Campaign, civilians, slavery, emancipation, remembrance, and metropolitan development. Authentic resources are chiefly landforms, trenches, foundations, and archaeology, not standing battle-period buildings or staged lines of soldiers.