The Act of Congress of Aug. 14, 1848, which created Oregon Territory, significantly revised the legislative branch of government. The territorial legislature, known as the Legislative Assembly, was made a bicameral body. It consisted of a nine-member Council and eighteen-member House of Representatives. The House could be increased in size, but could not exceed thirty members. Legislators were popularly elected and vacancies were filled by special election. Legislative sessions were limited to sixty days. The Legislative Assembly was prohibited from passing laws interfering with land claims and passing laws which taxed non-residents at a higher rate than residents. The Legislative Assembly was also prohibited from incorporating banks and financial institutions and from acquiring debts in the name of the territory.
Laws passed by Legislative Assembly were to deal with one subject only, named in the title, and had to be approved by Congress. Without both conditions, laws passed were considered null and void. The Act of Congress affirmed all laws passed by the provisional House of Representatives which were not in conflict with its provisions and required the Legislative Assembly to locate the territorial capital at its first session.
The first session of the territorial Legislative Assembly convened in Oregon City, July, 1849. A special session was held in May, 1850 to set times for convening regular legislative sessions. The first Monday in December was chosen. The second regular session was Dec. 2, 1850. The Legislative Assembly passed legislation making Salem the territorial capital. This law became the central issue in a political controversy. Two Supreme Court justices refused to recognize the legality of the act relocating the capital and held a Dec., 1851 Supreme Court session in Oregon City. One Supreme Court justice and the Legislative Assembly convened Dec., 1851 sessions in Salem. It wasn't until May, 1852, when Congress legalized the capital's move to Salem, that the territorial government functioned normally.
Gov. John P. Gaines called a special session of the Legislative Assembly in July, 1852. To spite the Whig governor, the Democratic legislature convened on July 26 and adjourned on July 29, refusing to conclude any business. The 1852 regular session convened December 6 and passed legislation creating new counties north of the Columbia, transferring the right to grant divorces from the Legislative Assembly to the court system, and chartering Willamette University.
The sixth regular session convened Dec. 4, 1854. On Jan. 13, 1855, it passed legislation making Corvallis the territorial capital. The seventh session was held in Corvallis. The territorial governor and treasurer remained in Salem after the U. S. Treasury Department ruled the move illegal. The legislature convened in Corvallis on December 3. It passed only one act - moving the capital back to Salem - before it adjourned. The Legislative Assembly reconvened in Salem on December 18. On December 30, the newly-built capitol building burned. The session was concluded in the Rector Building in downtown Salem.
The Oregon Constitutional Convention was held in Salem from Aug. 17 to Sept. 18, 1857. After some dissension over slavery, free blacks, education, and state boundaries, the Oregon Constitution was put to a vote of the people on Nov. 9, 1857. It was approved by a vote of 7,195 in favor and 3,215 opposed.
Elections were held June, 1858 to elect legislators in compliance with the ratified constitution. Two full sets of legislators were elected, one territorial and the other state. The Legislative Assembly met according to the constitution on July 5, 1858 to chose U. S. Senators and to inaugurate the state governor, secretary of state, and treasurer. Congress delayed acting on Oregon's statehood, so no state legislative session was held in 1858. The territorial Legislative Assembly convened Dec. 6, 1858 and adjourned Jan. 22, 1859 without accomplishing much. Oregon became a state on Feb. 14, 1859 and the state's first legislative session, a special session, was held May, 1859.