Short answers, pulled from the story.
The first recorded instance of an income tax in human history was introduced in the year 9 CE by Emperor Wang Mang of the Xin dynasty. This tax targeted net earnings from nonagricultural activities and was abolished thirteen years later in 22 CE.
Prime Minister William Pitt the Younger introduced the first graduated tax in Great Britain in 1799 to fund the French Revolutionary War. The tax was later reintroduced by Henry Addington in 1803 and permanently repealed in 1816 before Sir Robert Peel made it a permanent fixture in 1842.
The Sixteenth Amendment was ratified in 1913 to remove the legal obstacle to a federal income tax in the United States. This followed the Supreme Court ruling that the 1894 Wilson-Gorman tariff was unconstitutional under the Tenth Amendment.
In a territorial system, only local income is taxed, while in a residential system, tax residents are taxed on their worldwide income. The United States and Switzerland are notable examples of countries that impose the higher of regular income tax or an alternative tax based on capital.
The voluntary compliance rate is the proportion of people who pay their income taxes in full, on time, and voluntarily. This rate is higher in the United States than in countries like Germany or Italy, though it is very low in countries with a sizeable black market.