During the 19th century racism was constructed as a pseudo-scientific concept by writers such as Arthur Comte de Gobineau, Richard Wagner, Paul de Lagarde, Julius Langbehn, Houston Stewart Chamberlain and others. It was also the basis for antisemitism, which was developed during the same period. Racism and antisemitism did exist of course well before the 19th century, but this period added the pseudo-scientific foundation to the concept, mainly by adding distorted Darwinist and genetic findings.

Gobineau (1816 – 1882) published his foremost book “Essai sur l’inégalité des races humaines” during the years 1853 and 1855. One of his theses was the assertion, that the “white race” was superior to all other races. Mixture with other races would however reduce the quality of the white race and should therefore be sharply rejected.
Richard Wagner (1813 – 1883) and his personal environment (the so called  “Bayreuther Kreis” ) provided a German translation of Gobineau’s book and took care of its dissemination within the German speaking countries. Wagner however added two important aspects to Gobineau’s concept: The first was the contrast between the “Germanic-Aryan race” and the socially declassified “Jewish race” . The second aspect was the suggestion to “redeem” both by the destruction of the later. As a symbolic figure of Ahasver, the Jew condemned to restlessly wandering around, Wagner created the person of Kundry in Parsifal, who dies after having been baptized by Parsifal.

Paul de Lagarde (real name: Paul Bötticher, 1827 – 1891), professor for Oriental Studies, made propaganda for the redemption by a “German Christianity” , the journalist Julius Langbehn (“Rembrandt as an Educator”, 1851 – 1907) by a “German Art”.

The definition of Jews as a harmful anti-race to the noble “German-ness” indicated the transition from Christian Antijudaism to racial Antisemitism. From then on, Jews were not protected any more by converting to Christianity.

At the end of the 19th century the “Supergerman” Houston Stewart Chamberlain (1855 – 1927) provided a temporary finale in terms of ideological racism/antisemitism by publishing his foremost book “Die Grundlagen des 19. Jahrhunderts” (“Foundations of the 19th Century”). Chamberlain descended from a British family of Naval Officers and was raised by his aunt in France. He preferred biological studies in Geneva, Switzerland to a military career and felt strongly attracted by the German language and culture. Since 1885 he lived in a German speaking environment: Dresden, Vienna, Bayreuth. During this period he was increasingly  influenced by the racial and antisemitic theses of Richard Wagner and was informally appointed “Promotor in chief” of the “Bayreuther Kreis” after Wagner’s death in 1883.
His book was formally declared a “universal cultural history of Germany”, but under this cover Chamberlain condensed the multiple ideological concepts of Racism and Antisemitism during the 19th century as if under a burning glass. The publication found a strong reception among the German speaking educated classes up to the Emperor Wilhelm II.  In 1923, shortly before Hitler’s failed Munich revolt, the party leader visited the already seriously ill Chamberlain in Bayreuth and made a lasting positive impression on him. Full of enthusiasm Chamberlain dictated a letter, addressed to the “honored and dear Mr. Hitler” . Hitler was described as “the bearer of great hopes” for the German nationality.
Hitler promptly took advantage of the international reputation of the then well known writer and immediately published Chamberlain’s letter. At the same time he requested the ideological succession to the concepts of Wagner and Chamberlain: “The German-Nationalist Racism and Antisemitism”.  

For details see:
http://opus4.kobv.de/opus4-fau/frontdoor/index/index/docId/1971
Predecessors of the “Foundations……”: P. 25ff.
Influence of the Wagner/Chamberlain ideology on Hitler: P. 253ff.