On February 28, 1845, the U.S. Congress narrowly passed a bill that authorized the United States to annex the Republic of Texas if it so voted. The legislation set the date for annexation for December 29 of the same year. On October 13 of the same year, a majority of voters in Texas approved a proposed constitution that specifically endorsed slavery and the slave trade. This constitution was later accepted by the U.S. Congress, making Texas a U.S. state on the same day annexation took effect (therefore bypassing a territorial phase).