When, pursuant to or under color of authority of any general act, any special act or any act making a special provision in or about the subject matter of a general act, a high school shall have been established by the boards of trustees of two or more adjoining school districts located in the same county or adjoining counties in this State, or when the boards of trustees of two or more such school districts, by the adoption of resolutions, authorization of contracts for erection or in any other way jointly or as separate boards of trustees, shall have evidenced an intention to establish a high school district, a body corporate shall be and hereby is created and shall be deemed to have been created at and from the time of the first joint or separate action in any such case and for such purpose by two or more boards of trustees of school districts.