The Yellow Rose of Texas first appeared as a poem in 1836. It was first published as music in 1853 and became a popular Confederate marching song during the Civil War.
Texas legend has it that the Yellow Rose of Texas was a mulatto indentured servant of Colonel James Morgan named Emily West (a.k.a. Emily Morgan). On April 18, 1836 she was working on a flatboat as the Mexican Army marched through New Washington, Texas enroute to San Jacinto. Emily was kidnapped and given to General Santa Anna.
She was allegedly quartered in Santa Anna's tent on April 21, 1836 when Sam Houston's Texas Army attacked the Mexicans at San Jacinto. The Texans assembled in two lines stretching about 900 yards across. With cries of Remember the Alamo and Remember Goliad, they charged the encamped Mexican army.
The battle lasted less than 20 minutes, but the killing lasted several hours. When it was over 630 Mexicans were dead and 730 taken prisoner. The Texans lost 9 killed and 30 wounded. This horrible retribution was brought on by Santa Anna's policy of no quarter for the rebellious Texans when he had the upper hand.
Santa Anna was literally caught with his pants down when the Texans attacked. His lack of leadership at the critical moment is often cited as the reason for the confusion that doomed the Mexicans.
As part of the surrender agreement, Santa Anna ordered all Mexican troops remaining in Texas to immediately retreat south of the Rio Grande, ending the Texas war of independence from Mexico.