Question: The Battle of the Grapevine Creek was the last offensive event in what feud that spanned the years 1863-1891?

Context paragraphs:
Grapevine Creek: Grapevine Creek may refer to one of the following streams:

Battle of Le Transloy: The Battle of Le Transloy was the last offensive of the Fourth Army of the British Expeditionary Force (BEF) in the 1916 Battle of the Somme in France, during the First World War.  The battle was fought in conjunction with attacks by the French Tenth and Sixth armies on the southern flank and the Reserve/5th Army on the northern flank, against "Heeresgruppe Rupprecht" (Field Marshal Rupprecht of Bavaria) created on 28 August, from the 1st and 2nd armies of the dissolved "armeegruppe Gallwitz-Somme" and the 6th and 7th armies.  General Ferdinand Foch the commander of "groupe des armées du nord" (Northern Army Group) and co-ordinator of the armies on the Somme, was unable to continue the sequential attacks by the Anglo-French armies achieved in September, because persistent rain, mist and fog grounded aircraft, turned the battlefield into a swamp and greatly increased the difficulty of transporting supplies to the front over the few roads in the area and the land that had been devastated since 1 July.

Bad Pass Trail: The Bad Pass Trail, also known as the Sioux Trail, was established by Native Americans on the border of present-day Montana and Wyoming as a means of access from the Bighorn Basin in Wyoming to Bison-hunting grounds in the Grapevine Creek area of Montana.  Marked by stone cairns, the trail led across Bad Pass and was established in pre-Columbian times.  After Europeans arrived in the area it was frequented by fur trappers and mountain men, beginning in 1824.  Trappers assembled pack trains at the junction of the Shoshone River and the Bighorn River, using the Bad Pass Trail to avoid Bighorn Canyon.  The trail ended at the mouth of Grapevine Creek on the Bighorn, from which the pack train could float down the Bighorn on rafts to the Yellowstone River and then to the Missouri and on to St. Louis.

Peter Elstob: Peter Frederick Egerton Elstob was a British soldier, adventurer, novelist, military historian and entrepreneur.  In his writing he is best known for his lightly-fictionalized novel "Warriors For the Working Day" (1960) and his military history of the Battle of the Bulge, "Hitler's Last Offensive" (1971).  He joined the Republican Army in the Spanish Civil War, and later served in the Royal Tank Regiment in World War II, in which service he was promoted to sergeant and was Mentioned in Dispatches.  He joined International PEN in 1962 and served first as general secretary and later as vice-president for seven years during the 1970s, rescuing the organisation from financial failure; he also secured the future of the Arts Theatre Club in London in 1946.  He prospered as an entrepreneur with a facial product called Yeast Pac, with several partners.  In his obituary in The Guardian newspaper, Elstob was said to be

Battle of White Oak Road: The Battle of White Oak Road, also known as The Battle of Hatcher’s Run, Gravelly Run, Boydton Plank Road, White Oak Ridge was fought on March 31, 1865, during the American Civil War at the end of the Richmond-Petersburg Campaign and in the beginning stage of the Appomattox Campaign.  Along with the Battle of Dinwiddie Court House which was fought simultaneously on March 31, the battle involved the last offensive action by General Robert E. Lee's Confederate Army of Northern Virginia to stop the progress of Lieutenant General Ulysses S. Grant's Union Army (Army of the Potomac, Army of the Shenandoah and Army of the James).  Grant's forces were moving to cut the remaining Confederate supply lines and to force the Confederates to extend their defensive lines at Petersburg, Virginia and Richmond, Virginia to the breaking point, if not to force them into a decisive open field battle.

Battle of Dinwiddie Court House: The Battle of Dinwiddie Court House was fought on March 31, 1865, during the American Civil War at the end of the Richmond-Petersburg Campaign and in the beginning stage of the Appomattox Campaign.  Along with the Battle of White Oak Road which was fought simultaneously on March 31, the battle involved the last offensive action by General Robert E. Lee's Confederate Army of Northern Virginia attempting to stop the progress of Lieutenant General Ulysses S. Grant's Union Army (Army of the Potomac, Army of the Shenandoah and Army of the James).  Grant's forces were moving to cut the remaining Confederate supply lines and to force the Confederates to extend their defensive lines at Petersburg, Virginia and Richmond, Virginia to the breaking point, if not to force them into a decisive open field battle.

Battle of the Grapevine Creek: The Battle of the Grapevine Creek was a short battle between two large armed groups of the Hatfield Family and the McCoy family which was the last offensive event during the Hatfield–McCoy feud and marked the beginning of the Hatfields' defeat in the feud between the two families.

Hatfield–McCoy feud: The Hatfield–McCoy feud, or the McCoy-Hatfield feud or the Hatfield–McCoy war as some papers at the time called it, involved two rural families of the West Virginia–Kentucky area along the Tug Fork of the Big Sandy River in the years 1863–1891.  The Hatfields of West Virginia were led by William Anderson "Devil Anse" Hatfield while the McCoys of Kentucky were under the leadership of Randolph "Ole Ran'l" McCoy.  Those involved in the feud were descended from Ephraim Hatfield (born   1765) and William McCoy (born   1750).  The feud has entered the American folklore lexicon as a metonym for any bitterly feuding rival parties.  More than a century later, the feud has become synonymous with the perils of family honor, justice, and revenge.

Battle of Scimitar Hill: The Battle of Scimitar Hill ("Yusufçuk Tepe" (Dragonfly Hill)) was the last offensive mounted by the British at Suvla during the Battle of Gallipoli in World War I.  It was also the largest single-day attack ever mounted by the Allies at Gallipoli, involving three divisions.  The purpose of the attack was to remove the immediate Ottoman threat from the exposed Suvla landing and to link with the ANZAC sectors to the south.  Launched on August 21, 1915, to coincide with the simultaneous attack on Hill 60, it was a costly failure, in which the Turks were forced to use all their reserves in "severe and bloody fighting" far into the night, with some Turkish trenches lost and retaken twice.

Grammar Schools Act 1860: The Grammar Schools Act 1860 was passed by Queensland's first parliament in 1860 and allowed for the establishment of a grammar school in any town where £1000 could be raised locally.  Between the years 1863 and 1892, ten grammar schools were opened under the auspices of the Act.  The first of these was Ipswich Grammar School, which opened in 1863.

Supporting paragraphs: Battle of the Grapevine Creek Hatfield–McCoy feud
Answer: Hatfield–McCoy feud