Texas became the 28th state in 1845. The Texas quarter features an outline of Texas, the famous Lone Star (public domain image on Wikipedia).
The Lone Star State
The nickname The Lone Star State originates from the star on the 1836 flag of the Republic of Texas. The world-famous "Lone Star" is also found on the Texas flag, the great seal, the state commemorative quarter (above), and is recognized as the official state gemstone cut of Texas.