where was the fist high school founded?

Plano Senior High School (commonly Plano, Plano Senior, or PSHS) is a free public secondary school in Plano, Texas, United States serving eleventh and twelfth graders. The school is part of the Plano Independent School District, with admission primarily based on the locations of students' homes. Plano is a two-time Blue Ribbon School and a Texas Exemplary School, and has a longstanding history of academic excellence. Founded in 1891 as Plano Public School, serving both primary and secondary students, the school was by the mid-1910s sending a majority of its graduating classes on to college. Plano High School, created in 1952 by separating off the primary students into Mendenhall Elementary School, was immediately accredited by the Southern Association of Colleges and Schools, allowing its graduates to enter college without taking an entrance exam. In 1964, Plano High School integrated with the Frederick Douglass School, formerly Plano Colored School, and the integrated football team won the first of the school's seven state championships in 1965.[1] In 1975, the school moved to a new 96 acre (0.4 km²) campus with five buildings, very similar to the layout of a junior college, where it has remained since. Plano administers more Advanced Placement tests each year than any other school west of the Mississippi River and all but one school in the United States.[2] The school is accredited by the Texas Education Agency and the Southern Association of Colleges and Schools. Plano's graduating classes are among the largest for high schools in the United States. Plano's Class of 2005, with 1112 graduates, was the second-largest high school graduating class in the U.S. that year, behind only that of Plano East Senior High School. [3] Plano's mascot is the Wildcat.[4]