lol. of course i dont think that.
i think that the founders were influenced by the political situation in europe where the church was often a state unto itself or, in england's case, the state itself. they didnt want that repeated in america. however, that didnt mean not teaching about god in the public space, nor did it mean that putting up a christian symbol in a public space was unconstitutional. they were all about that.
our interpretation of what constitutes the "establishment" of religion would be beyond the scope of how the founders thought of it.