This book recovers the earliest epistolary activity of one of America’s most innovative and influential modernist poets. From 1902 to 1912, William Carlos Williams wrote more than 300 letters to his younger brother Edgar, an accomplished architect with whom Williams shared the desire to become ‘a great artist’. This collection of 200 letters sheds new light on the aesthetic thoughts and practices with which Williams was engaged for a full decade before his unique voice emerged in the forerunner to ‘Paterson’, ‘The Wanderer’ (1914). Providing a comprehensive introduction, exhaustive annotation, images of poetry and artwork, and hundreds of letters never before seen by scholars, this critical edition provides substantially new material on Williams and will be an important addition to the study of early American modernism.