Wikipedia has the usual basic rundown:
One of the tallest buildings in Dayton, The Biltmore was considered one of the finest hotels in America; playing host to some of the nation’s most powerful and celebrated men in the 20th century - such as JFK and Elvis
Was there a hotel those guys didn't stay in? Really: if it was old and brick and downtown, they stayed there.
Like so many hotels of its class, it was built in 1929, the last big statement of confidence.
It's senior living today.
By the way: I didn't buy the envelope, then discover the matchbook later. I bought them as a set. Some travelling salesman collected stuff he got from hotels, and put them all in envelopes - matches, paper, postcards, soap. He died; the heirs sold it all. I don't know who he was, but I'm trying to keep the basics of his collection together here, if possible.
The stationery had a logo at the bottom and a list of Hilton hotels. Minimax? That was the Hilton concept: maximum comfort / luxury for the minimum price. Of course, it could just as easily have meant the opposite.
The hotel today. Not so pink.