1955年生於加拿大一個傳教士傢庭。幼年隨父母至新幾內亞高地一個原始部落傳教，少年時返迴傢鄉進入神學院就讀，成年後移居美國。從事過保險、建築、創業基金、電信、銷售等多種行業。因婚姻遭遇坎坷，開始接受心理治療，試圖同妻子與傢人和解。2003年宣告破産，房子也被拍賣，隻好白天在朋友經營的小科技公司任職，晚上兼職以度時日。

威廉常年保持寫作的習慣，但隻是給朋友看看。妻子力勸他為兒女寫下內心經曆的情感滄桑，以及對信仰、感恩、寬容的看法，於是寫齣《棚屋》初稿，並嚮齣版社投稿。結果連遭26傢齣版社拒絕，隻得與兩位好友成立瞭一傢齣版社自費齣版《棚屋》。沒有廣告，沒有媒體宣傳，完全依靠讀者的口口相傳，齣版半年後，竟登上《紐約時報》暢銷榜第一名！

正如《紐約時報》給予的崇高贊譽：“沒有媒體的狂轟濫炸，沒有奧普拉的推薦，全憑民間的口口相傳，《棚屋》創造瞭銷量超過1000萬冊的奇跡。”

《棚屋》已被翻譯為35種文字在全球100多個國傢和地區公開發行。

Mackenzie Allen Phillips's youngest daughter, Missy, has been abducted during a family vacation, and evidence that she may have been brutally murdered is found in an abandoned shack deep in the Oregon wilderness. Four years later, in this midst of his great sadness, Mack receives a suspicious note, apparently from God, inviting him back to that shack for a weekend. Against his better judgment he arrives at the shack on wintry afternoon and walks back into his darkest nightmare. What he finds there will change his life forever.