Sunshine Assembly's roots can be traced back to a group of rainbow girls from Wolfe City who traveled every two weeks to attend Rainbow and Pledge at Roy Stanley Assembly #127. 

After a year or two the group had grown so large that two vans full of girls were making the trip, sometimes with an extra car thrown in for good measure.  The time had come to begin an assembly of our own.  Through the efforts of Mrs. Karen Hayes and Mrs. Barbara Grosvenor and the assistance of a Brother Mason or two, the lodges and chapters of Hunt County were solicited for their support, and the process of forming an assembly was begun.

On December 12th, 1998, Sunshine Assembly was instituted under Letters Temporary by Mrs. Barbara Grosvenor, Grand Visitor at Greenville Lodge #335 in Greenville Texas. 

On June 10th, 2000, Sunshine Assembly #LT became Sunshine Assembly #375, when Mrs. Marlene Dibrell, Supreme Deputy presided over the official constitution of Sunshine Assembly #375 as a regular assembly of the International Order of Rainbow for Girls, under the Grand Jurisdiction of Texas.