Short answers, pulled from the story.
Post-Impressionism began in 1886 with the final Impressionist exhibition and ended around 1914 when World War I started. John Rewald limited his scope to years between 1886 and 1892 while Alan Bowness extended the timeline forward to 1914.
Roger Fry coined the term Post-Impressionism in 1906 to describe a group of French painters who had moved beyond traditional techniques. He organized an exhibition called Manet and the Post-Impressionists at the Grafton Galleries in London three years after coining the phrase.
Paul Cézanne, Vincent van Gogh, Georges Seurat, Paul Gauguin, and Camille Pissarro were key figures in the movement. Canadian artists including Randolph Hewton, A.Y. Jackson, James Wilson Morrice, David Milne, Tom Thomson, and Emily Carr also adopted this label during the early twentieth century.
Neo-Impressionism emerged as a specific offshoot where artists like Seurat and Signac preferred terms such as Divisionism instead of Pointillism. They approached composition with meticulous scientific rigor by applying tiny dots of color in a method known as pointillism.
John Rewald limited his scope to years between 1886 and 1892 while Alan Bowness extended the timeline forward to 1914 marking the beginning of World War I. Critics continue debating how historians interpret the movement today regarding its scope dates and precise meaning attached to labels applied retrospectively.