Hispanic Heritage Month began as a week-long commemoration of Hispanic contributions to the United States in 1968 by the Johnson Administration. In 1988, the Reagan administration extended the celebration period to 30 days (from September 15 to October 15). While terms describing Hispanic and Latino identities have shifted and evolved since then, Hispanic Heritage Month continues to be the most recognized and universally adopted name.
Although people may interchange Latino with Hispanic, these pan-ethnic terms are not synonymous. The Spanish Royal Academy (RAE) offers a website and Q&A service called Foundation of Urgent Spanish (Fundéu) to resolve questions, doubts, and mistakes about Spanish language, grammar, usage, and more. In a 2011 article, Hispanic America, Iberian America, and Latin America are not synonyms the RAE explains:
“Hispanic America” refers to the group of Spanish-speaking American countries, the people are called Hispanic American and it is important to remember that this refers to what is related to Spanish America, without including Spain.
“Latin America” encompasses the group of countries in North and South America where languages derived from Latin are spoken: Spanish, Portuguese, and French. The name “América Latina” is an equivalent synonym. The people are called Latin American [or Latino].
To refer exclusively to Spanish-speaking countries it is more proper to use the specific term Hispanic America, or if Portuguese-speaking Brazil is included, the term Iberian America or Ibero-America should be used. The people are called Iberian Americans.
As we can see, the terms Hispanic and Latino are not synonyms: people from Brazil are Latinos because their language, Portuguese, is derived from Latin. But, they are not Hispanic because Portuguese is a language distinct from Spanish. Therefore, celebrating Hispanic and Latino Heritage Month instead of just Hispanic Heritage Month acknowledges the shared heritage and experiences of people from Latin America and Spanish speaking countries while honoring distinct cultural, linguistic, and historical contributions of both communities.