[Alabama – Georgia]
[Hawaii – Maryland]
[Massachusetts – New Jersey]
[New Mexico – South Carolina]
[South Dakota – Wyoming]
Hawaii
Hawaii became officially known as the “Aloha State” by a 1959 legislative act. Haw. Rev. Stat. 5-7
source: State Names, Seals, Flags, and Symbols by Benjamin F. Shearer, Barbara S. Shearer
Idaho
In 1863, Congress designated the Idaho Territory with the erroneous understanding that Idaho was a Shoshone word meaning Gem of the Mountains. In spite of the misunderstanding concerning the origin of the name the state continues to be known as the “Gem State” and the “Gem of the Mountains”.
source: State Names, Seals, Flags, and Symbols by Benjamin F. Shearer, Barbara S. Shearer
Illinois
Known unofficially as the “Prairie State”, a fitting nickname for a state that sets aside the third full week in September each year as Illinois Prairie Week to demonstrate the value of preserving and reestablishing native Illinois prairies.
source: State Names, Seals, Flags, and Symbols by Benjamin F. Shearer, Barbara S. Shearer
Indiana
“Hoosier State” came into general usage in the 1830s. John Finley of Richmond wrote a poem, “The Hoosier’s Nest,” which was used as the “Carrier’s Address” of the Indianapolis Journal, Jan 1, 1833. It was widely copied throughout the country and even abroad. A few days later, on January 8, 1833, at the Jackson Day dinner at Indianapolis, John W. Davis offered “The Hoosier State of Indiana” as a toast. And in August, former Indiana governor James B. Ray announced that he intended to publish a newspaper, The Hoosier, at Greencastle, Indiana.
Iowa
The “Hawkeye State” was first suggested by James G. Edwars as a tribute to indian leader Chief Black Hawk.
source: State Names, Seals, Flags, and Symbols by Benjamin F. Shearer, Barbara S. Shearer
Kansas
The nickname “Sunflower State” calls to mind the wild flowers of the plains of Kansas and the officially recognized state flower.
source: State Names, Seals, Flags, and Symbols by Benjamin F. Shearer, Barbara S. Shearer
Kentucky
Bluegrass is not really blue–it’s green–but in the spring, bluegrass produces bluish-purple buds that when seen in large fields give a rich blue cast to the grass. Early pioneers found bluegrass growing on Kentucky’s rich limestone soil, and traders began asking for the seed of the “blue grass from Kentucky.” The name stuck and today Kentucky is known as the “Bluegrass State”.
Louisiana
The nickname “Pelican State” is a tribute to the official state bird, the brown pelican, which is native to Louisiana.
source: State Names, Seals, Flags, and Symbols by Benjamin F. Shearer, Barbara S. Shearer
Maine
The “Pine Tree State” recognizes the white pine tree, an officially designated state symbol. Maine possesses over 17 million acres of forests.
source: State Names, Seals, Flags, and Symbols by Benjamin F. Shearer, Barbara S. Shearer ISBN 0313288623
1994
Maryland
According to some historians, Gen. George Washington bestowed the name “Old Line State” and thereby associated Maryland with its regular line troops, the Maryland Line, who served courageously in many Revolutionary War battles.
source: https://msa.maryland.gov/msa/mdmanual/01glance/html/nickname.html