Question: Who originally stated mexico as "the melting pot of all races?"
About the article "Mexico", section "Culture".

Candidate passages:
Zangwill supported the feminist and pacifist movements, but his greatest impact may have been as a writer who popularized the idea of the melting of the races into a single, American nation.
The hero of his widely-produced play, "The Melting Pot", proclaims: ""America is God's Crucible, the great Melting-Pot where all the races of Europe are melting and reforming... Germans and Frenchmen, Irishmen and Englishmen, Jews and Russians - into the Crucible with you all!
God is making the American."'"
The Melting Pot is a chain of franchised fondue restaurants in the United States, Canada and Mexico.
The Tampa, Florida based company had 142 locations as of August 2009, with 28 more locations under development.
The Melting Pot menu contains various cheese fondues, wines, salads, entrees of meat and seafood served with dipping sauces and oil or broth to be cooked in, and chocolate fondues.
It is part of Front Burner Brands. 
The melting pot theory of ethnic relations, which sees American identity as centered upon the acculturation or assimilation and the intermarriage of white immigrant groups, has been analyzed by the emerging academic field of whiteness studies.
This discipline examines the "social construction of whiteness" and highlights the changing ways in which whiteness has been normative to American national identity from the 17th to the 20th century.
In the late 19th and early 20th centuries, European immigration to the United States became increasingly diverse and increased substantially in numbers.
Beginning in the 1890s, large numbers of Southern and Eastern European immigrant groups such as the Italians, Jews, and Poles arrived.
Many returned to Europe but those who remained merged into the cultural melting pot, adopting American lifestyles.
By contrast, Chinese arrivals met intense hostility and new laws in the 1880s tried to exclude them, but many arrived illegally.
Hostility forced them into "Chinatowns" or ethnic enclaves in the larger cities, where they lived a culture apart and seldom assimilated.
The acquisition of Hawaii in 1898, with full citizenship for the residents of all races, greatly increased the Asian American population.
In the early 20th century, the meaning of the recently popularized concept of the melting pot was subject to ongoing debate which centered on the issue of immigration.
The debate surrounding the concept of the melting pot centered on how immigration impacted American society and on how immigrants should be approached.
The melting pot was equated with either the acculturation or the total assimilation of European immigrants, and the debate centered on the differences between these two ways of approaching immigration: "Was the idea to melt down the immigrants and then pour the resulting, formless liquid into the preexisting cultural and social molds modeled on Anglo-Protestants like Henry Ford and Woodrow Wilson, or was the idea instead that everyone, "Mayflower" descendants and Sicilians, Ashkenazi and Slovaks, would act chemically upon each other so that all would be changed, and a new compound would emerge?
"Nativists wanted to severely restrict access to the melting pot.
They felt that far too many "undesirables," or in their view, culturally inferior immigrants from Southern and Eastern Europe had already arrived.
The compromises that were reached in a series of immigration laws in the 1920s established the principle that the number of new arrivals should be small, and, apart from family reunification, the inflow of new immigrants should match the ethnic profile of the nation as it existed at that time.
National quotas were established that discouraged immigration from Poland, Italy and Russia, and encouraged immigration from Britain, Ireland and Germany. 
The literature of Mexico has its antecedents in the literatures of the indigenous settlements of Mesoamerica.
The most well known prehispanic poet is Nezahualcoyotl.
Modern Mexican literature was influenced by the concepts of the Spanish colonialization of Mesoamerica.
Outstanding colonial writers and poets include Juan Ruiz de Alarcón and Juana Inés de la Cruz.
In light of the various ethnicities that formed the Mexican people, José Vasconcelos in his publication La Raza Cósmica (The Cosmic Race) (1925) defined Mexico to be the melting pot of all races, biologically as well as culturally.
Other writers include Alfonso Reyes, José Joaquín Fernández de Lizardi, Ignacio Manuel Altamirano, Carlos Fuentes, Octavio Paz (Nobel Laureate), Renato Leduc, Carlos Monsiváis, Elena Poniatowska, Mariano Azuela ("Los de abajo") and Juan Rulfo ("Pedro Páramo").
Bruno Traven wrote "Canasta de cuentos mexicanos", "El tesoro de la Sierra Madre."
In the 18th and 19th centuries, the metaphor of a "crucible" or "(s)melting pot" was used to describe the fusion of different nationalities, ethnicities and cultures.
It was used together with concepts of the United States as an ideal republic and a "city upon a hill" or new promised land.
It was a metaphor for the idealized process of immigration and colonization by which different nationalities, cultures and "races" (a term that could encompass nationality, ethnicity and race) were to blend into a new, virtuous community, and it was connected to utopian visions of the emergence of an American "new man".
While "melting" was in common use the exact term "melting pot" came into general usage in 1908, after the premiere of the play "The Melting Pot" by Israel Zangwill.
The first use in American literature of the concept of immigrants "melting" into the receiving culture are found in the writings of J. Hector St. John de Crevecoeur.
In his "Letters from an American Farmer" (1782) Crevecoeur writes, in response to his own question, "What then is the American, this new man?"
that the American is one who "leaving behind him all his ancient prejudices and manners, receives new ones from the new mode of life he has embraced, the government he obeys, and the new rank he holds.
He becomes an American by being received in the broad lap of our great Alma Mater.
Here individuals of all nations are "melted" into a new race of men, whose labors and posterity will one day cause great changes in the world.
"In 1845, Ralph Waldo Emerson, alluding to the development of European civilization out of the medieval Dark Ages, wrote in his private journal of America as the Utopian product of a culturally and racially mixed "smelting pot", but only in 1912 were his remarks first published.
In his writing, Emerson explicitly welcomed the racial intermixing of whites and non-whites, a highly controversial view during his lifetime.
A magazine article in 1875 used the metaphor explicitly: ""The fusing process goes on as in a blast-furnace; one generation, a single year even-- transforms the English, the German, the Irish emigrant into an American.
Uniform institutions, ideas, language, the influence of the majority, bring us soon to a similar complexion; the individuality of the immigrant, almost even his traits of race and religion, fuse down in the democratic alembic like chips of brass thrown into the melting pot.""
In 1893, historian Frederick Jackson Turner also used the metaphor of immigrants melting into one American culture.
In his essay "The Significance of the Frontier in American History", he referred to the "composite nationality" of the American people, arguing that the frontier had functioned as a "crucible" where "the immigrants were Americanized, liberated and fused into a mixed race, English in neither nationality nor characteristics".
In his 1905 travel narrative "The American Scene", Henry James discusses cultural intermixing in New York City as a "fusion, as of elements in solution in a vast hot pot".
The exact term "melting pot" came into general usage in the United States after it was used as a metaphor describing a fusion of nationalities, cultures and ethnicities in the 1908 play of the same name, first performed in Washington, D.C., where the immigrant protagonist declared: