Photo from Kraft Foods' website.
The name (Pound Cake) comes from the fact that the original pound cakes contained one pound each of butter, sugar, eggs, and flour. No leaveners were used other than the air whipped into the batter. In the days when many people couldn't read, this simple convention made it simple to remember recipes.
A cake made of 1 pound of each of butter, sugar, eggs, and flour would have been very large and would have been able to serve multiple families. As years went by, the portions of the ingredients used were adjusted to make a smaller, lighter cake. However, the name of the cake stuck.
1700s- The Pound Cake is a British creation that dates back to the early 1700s.
1796 - In the 1796 cookbook American Cookery: or, The Art of Dressing Viands, Fish, Poultry and Vegetables, and the Best Modes of Making Puff-pastes, Pies, Tarts, Puddings, Custards and Preserves, and all kinds of Cakes, from the Imperial Plumb to plain Cake by Amelia Simmons, she includes two recipes. This was the first cookbook authored by an American and published in the United States.
1800s - By the mid 1800's pound cake recipes began to deviate slightly from the original formula to make a lighter cake.
1881 - The Pound Cake has traditionally been a popular dessert in the southern states. The first known cookbook written an African-American, Abby Fisher, called What Mrs. Fisher Knows About Old Southern Cooking. Mrs. Fisher, born a slave, somehow found her way to San Francisco soon after the Civil War and created a life and business there manufacturing and selling "pickles, preserves, brandies, fruits, etc. Mrs. Fisher could not read or write. It is said that her friends wrote down her recipes and helped her publish her cookbook. Her cookbook includes two Pound Cake recipes.
1900s - Artificial leaveners (baking powder/soda) were added. Today, pound cakes use different proportions of the same ingredients as the original formula to produce a lighter cake.