In 1862 the Texas Navy committed to its most ambitious project yet. Capitalizing on an emerging iron works industrial base, and after gathering practical knowledge of sail/steam operations on the Invincible, the Naval Staff proposed to construct a "composite" ship: iron frames, and a double layer wood hull under copper sheathing. Like her bigger cousin, this ship would also utilize a lifting screw propeller and make efficient use of breech-loading guns.
The design produced was the Brazos, a barquentine rigged ship, called a Corvette in the Royal Navy's vernacular.
Unfortunately, she came with a whopping pricetag: $370,000. The Invincible was a larger ship and had cost only $250,000. Congress balked when it could not fund the Brazos in a single fiscal year, and an agreement was reached to split the cost over two years. Expensive as she was, most Congressmen were unwilling to pass on the opportunity to support budding industries in Texas.
Though it delayed her commissioning by a year, Brazos was a handsome ship, and only two knots slower than the Invincible. Her armament of one 68lb RBL, one 32lb RBL, and six 20lb RBLs was more efficiently arranged than the Invincible.
A second ship, the Colorado, was authorized in 1864, but the economic crisis of the next four years rendered her incomplete when funds dried up. Her frames were scrapped on the ways and sold to recover as much of the $185,000 spent as possible.