The first marked burials were made in 1835, making this cemetery one of the oldest marked burial grounds in northeastern Illinois. Plots in the old Ottawa Section were sold for burial purposes beginning in 1847. The west edge of the Ottawa Section was platted for burials in 1862. St. Francis Catholic Church opened a church cemetery adjacent to the Ford Section in 1864. In 1865 the Ottawa Cemetery Association was formed. In 1882 the Ottawa Cemetery Association assumed management of cemetery grounds west of the St. Francis Cemetery known as both the New Cemetery and the Bushnell Section. In 1921 the Ottawa Cemetery Association was renamed the Ottawa Avenue Cemetery Association. About 1940 the OACA assumed oversight of the St. Francis Cemetery, it having been abandoned by the Church in favor of a newer cemetery outside of Ottawa. Today the Ottawa, Ford, St. Francis and Bushnell Sections comprise the Ottawa Avenue Cemetery of approximately 40 acres.

-From the Ottawa Avenue Cemetery website

Starting with four "blocks" in 1847 four different additions have increased the cemetery size to what it is today. The four original blocks and the first addition are what is called Ottawa Cemetery; the second part is the Ford Addition, the third the St. Francis Addition, and the final area is the Bushnell Addition.

Finding graves is relatively easy, Each section of the cemetery is coded as follows.

Ottawa Cemetery (along with the four original blocks): All burial plots start with the letters "OT" followed by the Lot Number then the Section Number. On the map be sure to find the Section Number first, which is usually the number after the dash symbol, then the Lot Number. Example: OT, 15-3. Note that there are some lots that have "1/2" in them.

Ford Addition: All burial plots start with the letters "FO" followed by the Lot Number then the Section Number. On the map be sure to find the Section Number first, which is usually the number after the dash symbol, then the Lot Number. Example: FO, 2-10, Grave 2 Note that some lots have "1/2" in them

St. Francis Addition: So far all of these burials start with the letters "BU" followed by the Section Number and then the Lot Number. Note that these are both numbers whereas the Bushnell Addition has a Lot Number and a Section Letter. The part that matters is the Lot Number as each Lot Number is used only once in the entire St. Francis Addition. All Lot Numbers are on the cemetery map. Example: BU, 40.51

Bushnell Addition. All burial plots start with the letters "BU" followed by the Lot Number and then a Section Letter (not a number). On the map be sure to find the Section Letter first and then the Lot Number. Example: BU, 5G

Mausoleum: Crypts in the mausoleum are coded "BU, MM," and then a number. The mausoleum is normally locked. Be sure to make arrangement with the cemetery if you need to see a burial crypt there.

Getting around in the cemetery is very easy as there are many roads so you never have to walk very far to visit a grave.