CREATE TABLE table_55991 ("School's name" TEXT, "School's namesake" TEXT, "Year opened" TEXT, "Principal" TEXT, "Mascot" TEXT)

What is the school namesake for Lincoln Junior High School?
SELECT "School's namesake" FROM table_55991 WHERE "School's name" = 'lincoln junior high school'
SELECT "School's namesake" FROM "table_55991" WHERE "School's name" = 'lincoln junior high school'