Hanson Improved 
Heading-type
70 to 80 days — The heads of 'Hanson Improved' are large, yellowish-green with frilled leaves and white hearts. Like other head-type lettuce plants, you must thin your plantings so that the plants are not crowded allowing heads to develop. The thinned plants (culls) should not be wasted. They make a great salad as a leaf lettuce. Additionally, when the mature heads are harvested, we still find the outer leaves to be tasty and perfectly suited for salads . . . bonus food. When you buy head lettuce at the market, all you are getting are the hearts.
This lettuce is an old family heirloom originating with the Hanson family of Maryland who had been cultivating it, "
... for over 70 years."
[1] In 1870, Colonel George Hanson sent seeds to Henry A. Dreer, a seedsman in Philadelphia, who recognized its merit and quickly began offering seeds in a limited introduction in 1871
[2] calling it simply, 'Hanson'.
By the early 1900s, it was being offered by 195 different seed merchants
[3] around the country; many of whom chose to change its name, a common practice at the time. Some of its synonyms include, Dreer's Hanson, Maule's Hanson, Bruce's Nonpareil, Simon's Nonpareil, Nonpareil, Los Angeles Market, Montreal Market, Hamilton Market, Evans' Hamilton Market, Toronto Market, Toronto Gem, Mastodon, Excelsior, Gardener's Friend, Gardener's Favorite, and Improved Hanson.
[3] Each packet contains one gram, which is approximately 500 to 600 seeds.