I'm going to have to agree. You should have gotten at least a few requests with that many queries sent out if your letter was not the problem. So, I'm going to also agree with the suggestion that you let us have a look and see what feedback we can offer. Better yet, post it to the Agent Inbox Group and let our agents have a look and give feedback. Keep in mind, that is not to say that the actual mss may not also need work. But, first things first, the letter is the first thing that agent's see. So let's start there. Once you post it to the Agent's Inbox, I will forward to the agents and see who is free to have a look. You may also post it here so non-agent members can give feedback.
Paul, I'm having the same problem. My novel is set in the late 70's and I think it is hurting my chances of publication. But I do see that as a challenge. I chose the decade because I am fascinated with it: the music, people, psyche. But more than my selfish reasons, I literally had to find a middle ground time-wise because in the second book my two MC's go backwards in time to reveal and fix something that happens in the first book, then in the third book they go to the future to prevent something from happening, all of this to better their time in the 1970's.
In a way, it is my job to make potential agents see how fab the 70's are, and how many people there are out there who want to revisit that time in our history. I've been racking my brain trying to find a good pitch, like calling it "retro fiction" which it is. What you and I have to ask ourselves is: why would someone want to read about the decade we chose? What can we do to make it sound exciting for them? Who is our audience? There are a lot of people who would want to revisit their teen years in the 1960's, would they perhaps want to read your book?
We have to make the agent or publisher see that our book is essential. I know it isn't easy, and I wish you the best of luck!
Your story sounds intriguing! But I think your synopsis is causing the rejections.
My gut instinct: Your query is too long and reads more like a short synopsis than a letter. The story summary part should be a couple paragraphs at the most, and it should emphasize the hook--the element that will make your story commercial. A well written query will include the basics (at least you don't have it in the post below) such as word count and genre. And it would also include information about the author's writing career--any national writing organizations, writing awards, etc. Finally, it should close with a thank you.
Does that help?