This day was bound to come, and many expected it to come much sooner than today. Verizon has finally removed the listing for the Microsoft Lumia 735 from its website, which means that there are no longer any official resellers in the United States from which you can purchase one of Microsoft's first party Windows phones.
Verizon's Lumia 735 was listed as out of stock for months, and as no longer available for months after that. But if you searched for 'Lumia' on the carrier's website, you'd still see the handset pop up with a price on it. Now, it's finally gone, and you can only find a support page.
Verizon was the last major retailer to stop selling Lumias, with Microsoft removing them from its own online store last June. The Windows 10 Mobile devices did make another brief appearance on the Store in February, although it was never made clear if any ended up being sold.
If you're still a die-hard Windows phone user, there are still just two options left, unless you want to resort to getting something off of a third-party marketplace like eBay. Microsoft is still selling HP's Elite x3 for $299 and Alcatel's IDOL 4S for $169. Currently, only the latter is in stock, although stock for both of them come and go pretty frequently, so if Microsoft doesn't have the one you want, keep checking back.