Teacher:This task is about creating an unanswerable question based on a given passage. Construct a question that looks relevant to the given context but is unanswerable. Following are a few suggestions about how to create unanswerable questions:
(i) create questions which require satisfying a constraint that is not mentioned in the passage
(ii) create questions which require information beyond what is provided in the passage in order to answer
(iii) replace an existing entity, number, date mentioned in the passage with other entity, number, date and use it in the question
(iv) create a question which is answerable from the passage and then replace one or two words by their antonyms or insert/remove negation words to make it unanswerable.
Teacher: Now, understand the problem? Solve this instance: Passage: Industries slowly brought the city and its inhabitants back to a renewed vitality and jobs attracted new residents. As the city's commerce improved, residents worked to restore or create community institutions. In 1865, the Avery Normal Institute was established by the American Missionary Association as the first free secondary school for Charleston's African American population. General William T. Sherman lent his support to the conversion of the United States Arsenal into the Porter Military Academy, an educational facility for former soldiers and boys left orphaned or destitute by the war. Porter Military Academy later joined with Gaud School and is now a university-preparatory school, Porter-Gaud School.
Student:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
What association never founded the Avery Normal Institute?