下午2:00左右,南軍第二軍的罗伯特·E·罗兹將軍以及朱巴尔·安德森·厄尔利將軍所率領的兩個師擊破分別據守於城外以北及西北的北軍第一軍及第十一軍外圍。南軍的爱德华·A·奥尼尔與小艾尔弗雷德·艾弗森所部兩旅在攻擊橡樹嶺(Oak Hill)以南的北軍第一軍约翰·C·鲁滨逊師時,遭受慘重傷亡。爾利師則因北軍第十一軍第一師師長弗朗西斯·C·巴洛(Francis C. Barlow)准將之失誤而得益:巴洛准將率領所部師朝突出於該軍戰線之外、易招來多方攻擊的布羅瑟高地(Blocher's Knoll,位於蓋茨堡正北方,今稱巴羅高地(Barlow's Knoll))推進,爾利師擊破了位於北軍第十一軍右翼的巴洛師,巴洛准將負傷被俘。
北軍於城外北邊及西邊之據點皆告陷落,北軍第十一軍軍長霍华德將軍下令撤至城南的墓園嶺(Cemetery Hill)高地,豪爾將軍先前將阿道夫·冯·施泰因韦尔准將的師留駐於此處作為預備隊。北軍波多馬克軍團司令米德少將一得知第一軍軍長雷諾茲少將陣亡,立即下令由他最信任的部下第二軍軍長漢考克少將(Winfield S. Hancock)接任戰場總指揮官,米德少將也指示漢考克少將應對於是否適合在蓋茨堡展開大型戰役作出判斷。漢考克少將對豪爾少將說道:「我認為這裡是我所見過最有利於打仗的天然地形了。」豪爾少將也同意漢考克少將的看法,於是漢考克少將如此回覆司令米德少將:「非常合適,長官,我選擇以此地作為戰場!」漢考克少將的決定,使敗退中的北軍提升了士氣,不過他在第一天的戰事中並未發揮具戰術意義的作用。
下午7:00左右,南軍第二軍的強森師對寇普嶺進行遲到的攻擊,帶頭展開第二軍的攻勢。嶺上的守軍為北軍第十二軍,但該軍大部分已被調集至左方以抵禦隆史崔特將軍的進攻。嶺上當時所餘兵力為乔治·S·格林(George S. Greene)准將率領的紐約客旅(第十二軍第二師第三旅)。由於葛林將軍前此便堅持構築堅強的防禦工事,後來又獲得第一軍與第六軍的增援,葛林將軍所部遂成功抵擋住了南軍的攻擊,南軍只佔領了北軍於嶺上低處放棄的部分防禦工事。
7月3日發生兩場大型騎兵遭遇戰。史都華將軍受命保護南軍左翼並作好擴充戰果的準備:在步兵登上墓園嶺後,側攻北軍的右翼,同時打擊其輜重與通訊線路。在蓋茨堡以東3哩(5公里)處,今稱“東騎兵場”之處(介於約克城與漢諾瓦公路間),史都華將軍的騎兵部隊遭遇北軍戴维·麦克默特里·格雷格准將所部一師及卡斯特准將所率領的密西根騎兵旅,在馬背上打了一場傳奇性的戰役,包含馬背上的徒手肉搏。卡斯特率領密西根騎兵旅衝鋒陷陣,牽制住漢普頓所部一旅,阻止史都華將軍達成迂迴敵後的目標。在皮克特衝鋒之後,北軍司令米德將軍命贾森·基尔帕特里克准將對隆史崔特軍位於大圓頂西南方的各步兵據點發動騎兵攻擊。埃隆·法恩斯沃思(Elon J. Farnsworth)准將抗議,認為此舉無謂,但仍遵命行動。方施渥斯准將於率領騎兵衝鋒時陣亡,所部傷亡慘重。
Bearss, Edwin C.Fields of Honor: Pivotal Battles of the Civil War. Washington, DC: National Geographic Society, 2006.ISBN 0-7922-7568-3.
Busey, John W., and David G. Martin.Regimental Strengths and Losses at Gettysburg, 4th ed. Hightstown, NJ: Longstreet House, 2005.ISBN 0-944413-67-6.
Carmichael, Peter S., ed.Audacity Personified: The Generalship of Robert E. Lee. Baton Rouge: Louisiana State University Press, 2004.ISBN 0-8071-2929-1.
Esposito, Vincent J.West Point Atlas of American Wars. New York: Frederick A. Praeger, 1959.OCLC5890637. The collection of maps (without explanatory text) is available online at theWest Point website.
Gallagher, Gary W.Lee and His Army in Confederate History. Chapel Hill: University of North Carolina Press, 2001.ISBN 978-0-8078-5769-6.
Gallagher, Gary W.Lee and His Generals in War and Memory. Baton Rouge: Louisiana State University Press, 1998.ISBN 0-8071-2958-5.
Glatthaar, Joseph T.General Lee's Army: From Victory to Collapse. New York: Free Press, 2008.ISBN 978-0-684-82787-2.
Harman, Troy D.Lee's Real Plan at Gettysburg. Mechanicsburg, PA: Stackpole Books, 2003.ISBN 0-8117-0054-2.
Hattaway, Herman, and Archer Jones.How the North Won: A Military History of the Civil War. Urbana: University of Illinois Press, 1983.ISBN 0-252-00918-5.
Longacre, Edward G.The Cavalry at Gettysburg. Lincoln: University of Nebraska Press, 1986.ISBN 0-8032-7941-8.
McPherson, James M.Battle Cry of Freedom: The Civil War Era. Oxford History of the United States. New York: Oxford University Press, 1988.ISBN 0-19-503863-0.
Martin, David G.Gettysburg July 1. rev. ed. Conshohocken, PA: Combined Publishing, 1996.ISBN 0-938289-81-0.
Nye, Wilbur S.Here Come the Rebels! Dayton, OH: Morningside House, 1984.ISBN 0-89029-080-6. First published in 1965 by Louisiana State University Press.
Pfanz, Harry W.Gettysburg – The First Day. Chapel Hill: University of North Carolina Press, 2001.ISBN 0-8078-2624-3.
Pfanz, Harry W.Gettysburg – The Second Day. Chapel Hill: University of North Carolina Press, 1987.ISBN 0-8078-1749-X.
Pfanz, Harry W.Gettysburg: Culp's Hill and Cemetery Hill. Chapel Hill: University of North Carolina Press, 1993.ISBN 0-8078-2118-7.
Rawley, James A.Turning Points of the Civil War. Lincoln: University of Nebraska Press, 1966.ISBN 0-8032-8935-9.
Sauers, Richard A. "Battle of Gettysburg." InEncyclopedia of the American Civil War: A Political, Social, and Military History, edited by David S. Heidler and Jeanne T. Heidler. New York: W. W. Norton & Company, 2000.ISBN 0-393-04758-X.
White, Ronald C., Jr.The Eloquent President: A Portrait of Lincoln Through His Words. New York: Random House, 2005.ISBN 1-4000-6119-9.
Wittenberg, Eric J., J. David Petruzzi, and Michael F. Nugent.One Continuous Fight: The Retreat from Gettysburg and the Pursuit of Lee's Army of Northern Virginia, July 4-14, 1863. New York: Savas Beatie, 2008.ISBN 978-1-932714-43-2.
Woodworth, Steven E.Beneath a Northern Sky: A Short History of the Gettysburg Campaign. Wilmington, DE: SR Books(scholarly Resources, Inc.), 2003.ISBN 0-8420-2933-8.