Editing 1826 (section)

=== July–September ===
* [[July 4]] – Former U.S. Presidents [[Thomas Jefferson]] and [[John Adams]] both die on the 50th anniversary of the signing of the [[United States Declaration of Independence]].
* [[July 15]] – The [[Congress of Panama]] adjourns after 24 days without an agreement on creating a federation of Latin American nations.<ref name=Reinhold/>
* [[July 25]] (O.S.: July 13) – Five leaders of the [[Decembrist revolt]] of [[1825]] in Russia ([[Pyotr Kakhovsky]], [[Pavel Pestel]], poet [[Kondraty Ryleyev]], [[Sergey Muravyov-Apostol]] and [[Mikhail Bestuzhev-Ryumin]]) are hanged in [[Senate Square (Saint Petersburg)|Senate Square, Saint Petersburg]], where they had launched their attempted coup d'etat. Other conspirators begin their journey into exile in [[Siberia]].
* [[July 26]] – [[Cayetano Ripoll]] becomes the last person to be executed by the [[Spanish Inquisition]] at its last ''[[auto-da-fé]]'', held in [[Valencia]].
* [[July]] – [[Ludwig van Beethoven]] puts the finishing touches on the [[String Quartet No. 14 (Beethoven)|String Quartet No. 14 in C♯ minor, Op. 131]], the jewel in the crown of [[Late string quartets (Beethoven)|his late string quartets]].
* [[August 10]] – The first [[Cowes Regatta]] is held on the [[Isle of Wight]], in the U.K.<ref>{{cite web|url=http://www.icons.org.uk/theicons/icons-timeline/1820-1840 |title=Icons, a portrait of England 1820-1840 |access-date=2007-09-12 |archive-url=https://web.archive.org/web/20070922055840/http://www.icons.org.uk/theicons/icons-timeline/1820-1840 |archive-date=September 22, 2007 |url-status=dead }}</ref>
* [[August 18]] – Scottish explorer [[Alexander Gordon Laing]] becomes the first European to reach [[Timbuktu]]<ref name="Pocket On This Day">{{cite book|title=Penguin Pocket On This Day|publisher=Penguin Reference Library|isbn=0-14-102715-0|year=2006}}</ref> but is murdered there on September 26.
* [[August 28]] – The town of [[Crawford Notch]], [[New Hampshire]] suffers a landslide; those killed include all seven members of the Willey Family, after whom [[Mount Willey]] is named.<ref>Stillman Rogers, ''It Happened in New Hampshire: Remarkable Events That Shaped History'' (Globe Pequot, 2012) pp.54-56</ref>
* [[September 13]] – [[William Morgan (anti-Mason)]] of [[Batavia, New York]], disappears mysteriously after being released from the jail in [[Canandaigua, New York|Canandaigua]] and agreeing to accompany his benefactor, a Mr. Loton Lawson.He is never seen in public again, and a number of witnesses will indicate later that on September 20, a man resembling Morgan was tied up and thrown into the [[Niagara River]] following a meeting of the Masonic Society.<ref>A. P. Bentley, ''History of the Abduction of William Morgan and the Anti-masonic Excitement of 1826-30, with Many Details and Incidents Never Before Published'' (Van Cise & Throop, 1874) pp.15-24.</ref>
* [[September 21]] – Construction of the [[Rideau Canal]] begins in Canada.