Lone Star State (Texas nickname)

Texas is called the “Lone Star State” from the single star in its flag.
 
“Why is Texas called the Lone Star State?”/“It’s their Yelp rating” is a modern joke.
     
 
Wikipedia: Flag of Texas
The flag of Texas is defined by law as follows:
 
“The state flag consists of a rectangle with a width to length ratio of two to three containing: (1) a blue vertical stripe one-third the entire length of the flag wide, and two equal horizontal stripes, the upper stripe white, the lower red, each two-thirds the entire length of the flag long; and (2) a white, regular five-pointed star in the center of the blue stripe, oriented so that one point faces upward, and of such a size that the diameter of a circle passing through the five points of the star is equal to three-fourths the width of the blue stripe. The red and blue of the state flag are the same colors used in the United States flag.”
 
The Texas flag is known as the “Lone Star Flag” (giving Texas its nickname of the “Lone Star State”). This flag was introduced to the Congress of the Republic of Texas on December 28, 1838, by Senator William H. Wharton. It was adopted on January 24, 1839 as the final national flag of the Republic of Texas.
 
When Texas became the 28th state of the Union on December 29, 1845, its national flag became the state flag. Texas law assigns the following symbolism to the colors of the Texas flag: blue stands for loyalty, white for purity, and red for bravery.The official Pantone shades for the Texas flag are 193 (red) and 281 (dark blue).
 
The Burnet Flag
The Lone Star Flag replaced the previous national flag (known as the Burnet Flag), which had been adopted on December 10, 1836. It consisted of an azure background with a large golden star, inspired by the 1810 “Bonnie Blue Flag” of the Republic of West Florida. Variants of the Burnet Flag with a white star, virtually identical to the Bonnie Blue Flag, were also common. 
 
50states.com
Texas
A single star was part of the Long Expedition (1819), Austin Colony (1821) and several flags of the early Republic of Texas. Some say that the star represented the wish of many Texans to achieve statehood in the United States. Others say it originally represented Texas as the lone state of Mexico which was attempting to uphold its rights under the Mexican Constitution of 1824. At least one “lone star” flag was flown during the Battle of Concepcion and the Siege of Bexar (1835). Joanna Troutman’s flag with a single blue star was raised over Velasco on January 8, 1836. Another flag with a single star was raised at the Alamo (1836) according to a journal entry by David Crockett. One carried by General Sam Houston’s Texian army (which defeated Mexican General Santa Anna at the Battle of San Jacinto ) may have been captured and taken to Mexico. Another “lone star” flag, similar to the current one but with the red stripe above the white, was also captured the following year (1837) and returned to Mexico. The “David G. Burnet” flag, of “an azure ground” (blue background) “with a large golden star central” was adopted by the Congress of the Republic of Texas in December of 1836. It continued in use as a battle flag after being superseded in January of 1839. The 1839 design has been used to symbolize the Republic and the “Lone Star State” ever since.
source: http://www.main.org/boyscout/texas.htm 
 
(Oxford English Dictionary)
lone star, the single star on the state flag of Texas, hence called the Lone Star State. Also Lone Star Stater, a Texan.
1843 W. B. DEWEES Lett. from Early Settler Texas (1852) 246 The lone star of Texas shall continue to wave proudly in the air as long as one brave Texan remains to defend it.
1845 Congress. Globe 28th Congress 2 Sess. App. 78/3 The ‘lone star’ has found a place upon the democratic banners.
1848 Ibid. 30th Congress 1 Sess. App. 973/1 Texas was then a ‘lone star’. She is now one of thirty.
1860 Ibid. 5 Dec. 11/3 There is a clog in the way of the lone-star State of Texas in the person of her Governor.
1873 J. H. BEADLE Undevel. West 805, I am proud to find him in honor and position among the ‘Lone Star Staters’.
1873 Z. N. MORRELL Flowers & Fruits (ed. 2) 20 Sam. Houston was then in Texas..intending..to set in motion ‘a little two-horse republic under the Lone Star’.
1886 B. P. POORE Perley’s Reminisc. I. 315 It took him only from February 28th to April 12th to conclude the negotiation which placed the ‘Lone Star’ in the azure field of the ensign of the Republic.
1909 ‘O. HENRY’ Roads of Destiny xvi. 267 The Lone Star State never yet failed to grant relief, [etc.].
 
1 March 1837, Rhode-Island Republican, pg. 2:
The Texan Congress has adopted a national seal and flag; the seal a single star with the legend “Republic of Texas”—the flag on azure ground with a large golden star in the centre. The naval flag is union blue star central, and thirteen stripes prolonged, alternate red and white.
   
11 August 1837, Richmond (VA) Enquirer, “TEXAS,” pg. 4:
In the first impulse of its revolution, there was more need of stout hearts and strong arms than of political wisdom or social refinement, and all who rallied to the banner of the “lone star,” were welcome, because the barbarians had trodden down the liberties of the country with an iron heel, and the only thought was for their expulsion.
   
The Portal to Texas History
3 February 1838, Telegraph and Texas Register (Houston, TX), pg. 3, col. 3 ad:
PROPOSALS
TO PUBLISH AT THE CITY OF HOUSTON A NEW PAPER, TO BE CALLED THE
BANNER OF THE LONE STAR 
 
9 January 1839, Telegraph and Texas Register (Houston, TX), pg. 2:
An act amending an act entitled an act adopting a national seal and standard for the Republic of Texas, approved on the 10th December, 1836.
(...)
Sec. 3. Be it further enacted, That from and after the passage of this act, the national standard of Texas shall consist of a blue perpendicular stripe, of the width of one third of the whole breadth of the flag, with a white star of five points in the centre thereof, and of two horizontal stripes of equal breadth, the upper stripes white, the lower read, of the length of two-thirds of the whole length of the flag, any thing in the act to which this is an amendment, to the contrary notwithstanding.
       
19 May 1846, New-York (NY) Daily Tribune, “Affairs at Washington,” pg. 2, col. 3:
“Galveston” states that the “Lone Star State” will conquer all of Mexico—stopping only at the Isthmus?
 
27 May 1846, Emancipator and Republican (Boston, MA), pg. 19:
“Galveston” states that the “Lone Star State” will conquer all of Mexico—stopping only at the Isthmus?
   
The Portal to Texas History
23 January 1847, Northern Standard (Clarksville, TX), pg. 1, col. 2:
‘The loss of this neat relic of our former nationality [says the Democrat of Wednesday,] is sensibly felt by the citizens of Austin, and should strike a tender chord in the breast of every son of the Lone Star State.”
 
27 May 1848, Northern Standard (Clarksville, TX), pg. 3:
The following is the toast drunk to the “Lone Star State” viz:...