Included within the Bonhams & Butterfields' Fine Books & Manuscripts auction are two remarkable documents dating from the birth of the State of California:

The first is a registrar leaf from the 1849 California State Constitutional Convention signed and inscribed by 46 members of the delegation.

Signatures include those of Henry W. Halleck who would later serve as a Union general in the Civil War; Robert Semple, president of the Convention; and John Sutter, owner of the land where gold was first discovered in California.

Each leaf includes the signatures, place of birth, residence, and age of each Delegate "convened in general Convention on the 1st day of September 1849 "at Monterey, to frame a State Constitution for California."

The accompanying document is believed to be a preliminary signatory page prepared for a printed version of the Constitution.

The text at the upper margin reads: "Signatures of the Delegates assembled in Convention in Colton Hall September & October 1849 to form the first Constitution of California."

Each individual signature sits on a penciled line, and spaces for the five delegates who haven't signed are marked with annotations.

In preparation for statehood, California Military Governor Bennet Riley issued a proclamation in June 1849 calling for the election of delegates to a convention designed to craft a state constitution.

Riley called for the election of 37 delegates, apportioning representatives to the various settlements in California; 48 delegates would eventually serve.

Only a handful of delegates were native-born Californians, the rest were from the east coast, south, and Europe.

The Convention was in session 43 days; members adopted the Constitution on October 10 and adjourned three days later.

In preparation for the state's admission to the union, the constitution clearly spells out California's identity as a free state, declaring that "all men are by nature free and independent" and that "Neither slavery, nor involuntary servitude ... shall ever be tolerated in this state."

The documents have been passed down through an old California family with ties to the Santa Clara valley region.

The two documents are expected to bring $10,000-15,000 when auctioned tomorrow to coincide with the 160th anniversary of the Convention.