In early January 1842 the Sixth Congress of the Republic of Texas passed a joint resolution to establish and organize the county of La Baca. On January 12 President Sam Houston vetoed the resolution on the grounds that it was in violation of Section 5 of Article 1 of the Texas Constitution, which ensured each county representation in the House of Representatives. On January 29 the House voted to reconsider the resolution and, with the concurrence of the Senate, passed it over Houston's veto. At the same time the legislature attached the new county to the fourth judicial district of the republic. According to the resolution, the County of La Baca would contain parts of Fayette, Gonzales, Victoria, Jackson and Colorado counties.
It was abolished later in 1842 with all judicial counties, and became La Vaca? Lavaca County 7/13/1846 immediately after Texas joined the Union. -Handbook of Texas Online: La Baca County, Defunct Counties