How did the country of Turkey get its name?

Turks was the name of the indigenous people and the word may have meant 'strong and powerful'. The bird turkey was so named in error and originally used for African guinea fowl imported from Guinea and through Turkey. The American turkey eaten at Thanksgiving and Christmas was wrongly identified as a species of African guinea fowl, so was given the same name.
Brewer's Dictionary of Names.

Mustafa Kemal Pasha, who became known as Kemal Ataturk (Father of the Turks), was the first ruler of modern Turkey as opposed to the former Ottoman Empire. He WAS a great ruler, as Turkish exile says, modernising a decrepit and antiquated country. He introduced the Roman alphabet, reformed the legal system and gave equal status to women. While often given to frivolity myself, I agree with exile that tim's remarks are somewhat offensive.

'Turkey was named for the Turks, believe it or not. Turk can mean either 'a citizen of the modern state of Turkey' or more broadly, 'an individual of the Turkic-speaking people.' The many Turkic languages are spoken not only in Turkey but also in a large area of central Asia and in northern Siberia. The real question is the origin of the name Turk. The word is essentially the same in many languages, including English, Turkish, Arabic, and Persian (Farsi). It probably comes from some Turkish root, but there's no consensus on which one. It may be one root meaning 'strong' or 'vigorous' (according to the American Heritage Dictionary) or it may be another meaning 'the people' (according to the Encyclopedia Americana).
There are a couple of other theories of how the country got its name, both wrong. The first has it that the country was named after the first leader of the Turkish Republic, Mustafa Kemal Ataturk. But like most Turks, Mustafa didn't have any surname at all until 1934, when he chose Ataturk ('Father of the Turks') for himself. He had already given the country its western-influenced name Turkiye several years earlier. During the period of the empire, the Turkish name for the country had nothing to do with the Turks. Rather, it was named for the Osman (Ottoman) dynasty that ruled it. Another theory has it that the English named the country after the bird, as a taunt. But the country was already called 'Turki' or 'Turkeye' in English by 1275, hundreds of years before the bird was known in the Old World.
https://en.wikipedia.org/wiki/Name_of_Turkey