The brilliance and power of Eisenstein's work will remain unappreciated for a long time in part because it will be almost 125 years before the publication of his Collected Works. In the foreword to their second edition , the eminent twentieth century mathematician André Weil reviews Eisenstein's mathematical contributions, in particular
``the impressive series of papers on elliptic functions and their application to the higher reciprocity laws . [The] series ends up with a great paper, the Genaue Untersuchung of 1847, which excited Kronecker's enthusiasm when he discovered it late in life, and which still deserves ours; it is nothing less than the sketch of a complete theory of elliptic and modular functions, based on principles essentially distinct from those of Jacobi and from those of Weierstraß (while anticipating him by nearly fifteen years), but, as I have more amply demonstrated elsewhere, its principles can be profitably applied to important current problems.''
Late in the 19th century, Baumgart  will write a survey of the many different proofs of the Fundamental Theorem given by then. Unfortunately, he will misunderstand and overlook most of the beautiful features of Eisenstein's geometric proof, mentioning only how he counts the points in a rectangle to avoid my technical argument above for adding the two series with interchanged roles for p and q. Sadly, he will miss Eisenstein's algebraic form of my Lemma, as well as his geometric way of representing my transformations. Subsequent mathematicians, probably relying on Baumgart's survey rather than reading Eisenstein's original paper, will perpetuate this oversight. Let me just mention Bachmann's early 20th century book on number theory  as an example.
Only shortly before the dawn of the 21st century will this injustice be rectified, when mathematicians of the distant future rediscover and fully appreciate the neglected and spectacular parts of Eisenstein's geometric proof of the Fundamental Theorem of higher arithmetic.