Icon books is an adult non-fiction publisher that was founded in 1992. You can get a good feel for the books they publish here. The books they publish tend to fall into the following categories, Biography and Memoir, Business and Self Help, History and Current Affairs, Lifestyle and Travel, Literature & Language, Philosophy, Popular Culture, Popular Science, Psychology, and Sport.
They books they publish are distributed through Publishers Group West, an imprint of Ingram that is pretty selective and actively distributes books in stores.
They are open to unsolicited adult non-fiction manuscripts only. They are not interested in any work outside of that. Submissions are made via email and involve downloading and filling out a submission form, which you can see here. The form is pretty basic and only one page long. It covers most of the territory a proposal would. They are not open to submissions via any other format, including mailed submissions.
They will send an email acknowledging that they’ve received the submission. They will only contact you again after that if they are interested in seeing more. You will not receive a rejection from them. See their submission guidelines here.
Emily Harstone is the author of many popular books, including The Authors Publish Guide to Manuscript Submissions, Submit, Publish, Repeat, and The 2023 Guide to Manuscript Publishers. She regularly teaches courses on writing and publishing at The Writer’s Workshop at Authors Publish. You can follow her on Facebook here.