What does the 'Old Number 7' on the Jack Daniel's bottle mean? Were there Old Numbers 1 through 6?

As it turns out, even the people at the company don't know the significance of "Old Number 7." This is a page from the official website (you may need to enter your birthdate to show that you are over 21 to proceed to this link):

http://www.jackdaniels.com/en-us/our-story

While a college student in Tennessee, not far from the Jack Daniels distillery, the story I heard was that in Mr. Daniels' first distiller's competition he was assigned number 7 as an entrant. May or may not be true, but the locals all believed it.

I thought they knew the significance. I saw it in a documentary on whiskey. A shipment marked No. 7 was lost. The first part of it sold so quickly that the sellers requested more of the No. 7. When JD found the lost portion of the shipment, they stamped it Old No. 7 to make sure the customers knew it was a part of the original number 7 shipment and not a new brew.

There are many theories as to what the No. 7 represents, but in truth it's a mystery that died with Jack Daniel. Jack's whiskey has won 7 medals in world competitions, so it may be true that he was not only a great whiskey distiller, but claivoyant as well.

storify.com/OmarKattan/jack-daniel-s-the-story-of-old-no-7 webpage no longer exists

Legend has it that Old No. 7 referred to Jack and his six friends who had the original idea for this special type of whiskey. Legend also reports that they enjoyed many a long lazy day, evening and night sampling and perfecting until the ultimate whiskey was born.

https://en.wikipedia.org/wiki/Jack_Daniel%27s

Some say that Jack Daniel had 7 girlfriends, or that the way he wrote his “J” looked like a 7. Some say he chose the number 7 simply because it’s lucky.
One story goes that the recipe for Jack Daniel’s was Mr. Jack’s 7th recipe or 7th trial batch.
Another story says that it was the railroad shipping number on a barrel. We’ll never know for sure – Mr. Jack took that secret to the grave.

On wikipedia they quote the legend claiming that JD and his six friends invented the No7 whiskey; therefore, No. 7 stands as a tribute to his friends.

http://ofarmsandaman.blogspot.com/2010/02/jack-daniels-old-no7.html