Grogan who initially trained with local painter, John Butts, noted Dutch painters such as Hobbema and Heemskerck as his key influences. He began life as an apprentice to his father, a turner and block maker, but had a love for the arts and taught himself to draw. At his fathers request, he enlisted in the British army and served in America during the War of Independence. Little, if any, is known of the paintings he produced in the new world. Grogan went on to produce numerous oil and watercolour paintings depicting landscape and genre scenes of his native Cork. His son also became a painter, achieving some success. His 1780 painting, View of Cork, is considered an important record of the city's history.