The building, built in 1884 and expanded with an additional floor in 1893, was put up for auction in 1894 and acquired by the Municipal Government for 3.62 contos de réis, initially serving as a prison, school, and police station.

[12][13] On August 5, 1976, the Historical Archive was officially created, being installed in a small wooden house in the back of the Museum, where the conditions were extremely precarious.

[18][19] However, the renovation was superficial,[20] and from this time on the interest of the public decreased significantly, investments ceased, cataloguing and acceptance of new donations was halted, many pieces went astray, and many others were loaned and never returned.

[14] In 1997, the museum started to manage the chapel in the replica of the Old Caxias in the Grape Festival Park, and collaborated in the revitalization project of the set of buildings.

The construction of a new annex at the back of the building made it possible to create a larger technical reserve and to gather in one space all the collection that was scattered in several places and was deteriorating due to poor storage conditions.

[21][20][27] It has more than 12,000 pieces that illustrate the previous indigenous occupation of the territory, immigration, the initial possession and cultivation of the land, and the developments and changes in the main activities and professions that occurred in the area of Caxias do Sul during the urbanization process.

[7][27] The collection includes indigenous artifacts; travel gear; machinery and tools used in agricultural activities; iron, glass, chinaware, and copper objects used in kitchens and workshops; furniture, shoes, and clothing; technical and musical instruments and accessories for personal use; pieces of sacred art, and, finally, objects derived from service, commerce, leisure, culture, and toys.

[7][27] Among the most interesting individual pieces are a rustic bean sifting machine; a full-wall cupboard with numerous bottles of medicine and pharmaceutical objects, which belonged to a former pharmacy that was demolished; a cash register; a large painting depicting St. Mark the Evangelist; a group representing the Madonna of the Snows and Child and a group depicting St. Michael defeating the devil, by Pietro Stangherlin; a statue of Thérèse of Lisieux aux roses (Teresa de Lisieux) by Michelangelo Zambelli; a processional statue (Portuguese: estátua de roca) of the Blessed Virgin of Mercy by Tarquinio Zambelli, and an anonymous Pietà with archaic features.