Short answers, pulled from the story.
Thomas Cannon published his work Ancient and Modern Pederasty Investigated and Exemplify'd in 1749. This text stands as one of the earliest known defenses of homosexuality in English literature.
France became the first nation to decriminalize homosexuality in 1791 during the French Revolution. The Duchy of Warsaw followed suit when introducing the Napoleonic Code in 1808, and by 1830 the Brazilian Empire omitted sodomy provisions from its new Penal Code.
The Wolfenden Report recommended that homosexual behavior between consenting adults in private should no longer be criminal offenses. This report eventually led to passage of the Sexual Offences Bill 1967 which decriminalized homosexual acts between two men over twenty-one years old in England and Wales.
Iceland legalized same-sex marriage through a unanimous vote counting forty-nine yes votes against zero no votes on the 11th of June 2010. Argentina became the first Latin American country permitting such unions shortly thereafter.
In Obergefell v Hodges decided on the 26th of June 2015, the U.S. Supreme Court ruled five-to-four that the Constitution requires allowing same-sex couples to marry regardless location within the United States. This decision made America the seventeenth country fully legalizing same-sex marriages.