It depends on what kind of visa you want/need. Marriage (and, I believe, retirement) visas are not issued anywhere in the United States.
It seems that as rules and regulations change in Thailand, this is not communicated to the consulates or is misinterpreted.
If you are a U.S. citizen, come into the country without a visa. You will be issued a 30-stay visia. If you want another kind of visa, begin the process immediately.
When I first came to Thailand in 2011, I was going to apply for a retirement visa in the U.S., before I left. After lots of calls to the embassy in Washington D.C., no one could answer any questions. Finally, I saw and ad for Siam Legal and sent them an email. They confirmed that you can't do a retirement visa in a foreign country. They secured a 90 business visa for me, and helped me with the retirement visa once I got to Chiang Mai. I believe their bill was just under $5,000. Help with visas has gone up, but the process at immigration has improved considerably.
Good luck