David S. Richeson, in his book, Tales of Impossibility, tells the story of Pierre Wantzel. I'll quote bits and pieces:

In 1837 ... Wantzel proved that it was impossible to trisect every angle, to construct every regular polygon, and to double the cube.... The result came with a deafening silence. Not only was it not publicized at the time, prominent mathematicians even a century later did not know who proved the impossibility results.

Wantzel published his article in one of the premier journals of the time [J. Math. Pures Appl.]. And yet his work was almost immediately forgotten.... On December 18, 1852, Sir William Rowan Hamilton wrote to De Morgan, "Are you sure that it is impossible to trisect the angle by Euclid?" De Morgan replied on Christmas Eve, "As to trisection of the angle, Gauss' discovery increases my disbelief in its possibility."

In 1897 Felix Klein wrote a book called Famous Problems of Elementary Geometry: The Duplication of the Cube, the Trisection of an Angle, the Quadrature of the Circle. In the introduction he wrote [The proof of the impossibility of the duplication of the cube and the trisection of an arbitrary angle] "is implicitly involved in the Galois theory as presented today in treatises on higher algebra." Klein did not mention Wantzel. Moreover, further muddying the water he incorrectly credited Gauss with the proof of the impossibility of constructing all regular polygons.

In 1914 Raymond Archibald ... wrote, "Who first proved the impossibility of the classic problem of trisection of an angle? I have not met with a statement of this fact in any of the mathematical histories...."

James Pierpont [1895] did squash the Gauss misinformation, but he did not give Wantzel credit.

Many mathematics books ... in the late nineteenth and early twentieth centuries discussed the classical problems but did not include their eventual solutions.... Often they misattributed the polygon proof to Gauss. As for the proofs of impossibility for angle trisection and the doubling of the cube – they either didn't know whether it had been proved, didn't know who gave the first proof, or misattributed the proof.

Repeatedly throughout the twentieth century – even as late as 1990 – mathematicians and historians of mathematics overlooked Wantzel and his contributions [a footnote refers to p. 152 of Eves' 1990 An Introduction to the History of Mathematics].