April 22
- 1836 - Texas Revolution: A day after the Battle of San Jacinto forces under Texas General Sam Houston capture Mexican General Antonio López de Santa Anna.
- 1863 - American Civil War: Grierson's Raid begins – troops under Union Colonel Benjamin Grierson attack central Mississippi.
- 1898 - Spanish–American War: The United States Navy begins a blockade of Cuban ports and the USS Nashville captures a Spanish merchant ship.
- 1915 - The use of poison gas in World War I escalates when chlorine gas is released as a chemical weapon in the Second Battle of Ypres.
- 1930 - The United Kingdom, Japan and the United States sign the London Naval Treaty regulating submarine warfare and limiting shipbuilding.
- 1944 - World War II: Operation Persecution initiated – Allied forces land in the Hollandia area of New Guinea.
April 22
- 1836 - Texas Revolution: A day after the Battle of San Jacinto forces under Texas General Sam Houston capture Mexican General Antonio López de Santa Anna.
- 1863 - American Civil War: Grierson's Raid begins – troops under Union Colonel Benjamin Grierson attack central Mississippi.
- 1898 - Spanish–American War: The United States Navy begins a blockade of Cuban ports and the USS Nashville captures a Spanish merchant ship.
- 1915 - The use of poison gas in World War I escalates when chlorine gas is released as a chemical weapon in the Second Battle of Ypres.
- 1930 - The United Kingdom, Japan and the United States sign the London Naval Treaty regulating submarine warfare and limiting shipbuilding.
- 1944 - World War II: Operation Persecution initiated – Allied forces land in the Hollandia area of New Guinea.