In Tune with the Infinite — The defining text of American New Thought: Ralph Waldo Trine's 1897 argument that the human soul is one with the Infinite Spirit, and that opening to this divine inflow brings health, peace, power, and plenty.
The Science of Getting Rich — The foundational text of American New Thought: Wallace D. Wattles' 1910 argument that there is a Thinking Substance pervading all things, and that anyone who impresses their thought upon it — in 'a Certain Way' — will certainly get rich.