Abstractionism developed in the early 20th century, influenced by styles like Impressionism, Post-Impressionism, Fauvism, and Cubism. Key artists like Kandinsky, Mondrian, and O'Keeffe pioneered geometric and non-geometric abstraction by focusing on spiritual expression through color, form, and the essential qualities of subjects rather than realistic representation. Their abstract paintings had a significant impact and influenced other areas like architecture, fashion, and design in moving art and visual culture into the modern world.