when was it's inception?
The idea of a new coin design was put forth in 1904.
Lincoln cent
t Roosevelt's instructions, the Mint hired Saint-Gaudens to redesign the cent and the four gold pieces: the double eagle ($20), eagle ($10), half eagle ($5), and quarter eagle ($2.50). As the designs of those pieces had remained the same for 25 years, they could be changed without an act of Congress. The Indian Head cent, which the Lincoln cent replaced, had been introduced in 1859.

Saint-Gaudens originally conceived a flying eagle design for the cent, but at Roosevelt's request, developed it for the double eagle after learning that by law, an eagle could not appear on the cent.
what is the lincoln cent? A one-cent coin.
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Lincoln cent [SEP] Inception
coin had featured an actual person (as opposed to idealized personifications, as of "liberty"). Many writers had suggested a Lincoln half dollar, but that coin's design had been changed in 1892 and could not yet be altered without congressional approval. By then a lame duck in office, Roosevelt was reluctant to involve Congress. In late 1908, Roosevelt sat for sculptor Victor David Brenner, who was designing a medal for the Panama Canal Commission. While the contents of their conversations were never recorded, it appears they discussed Roosevelt's plans for coinage redesign. Roosevelt had admired a 1907 plaque of Lincoln which the artist had produced.