As 1964 drew to a close, with a failed referendum behind them and an overcrowded library in front of them, the Cook Memorial Library Board set about regrouping and looking for their next course of action.
In February of 1965 head librarian Mrs. Littler announced her plans to retire  but wouldn’t do so for a year or so. She was still around in September of 1965 to attend a meeting with other regional libraries about forming a library system . While this specific plan did not materialize, the idea of libraries forming cooperative service arrangements continued to be popular. A local library system would come to fruition several years later.
Meanwhile, the Library Board had to do something about the lack of space in their library building. In July of 1965 they came up with policy statements that would guide their decisions going forward and help them communicate their ideas to the architects.  Cone and Dornbush again came up with plans, but this time the plans were less controversial.
The year 1966 was a busy one for the Libertyville Township Library Board. In March of 1966 they signed a 5-year contract for reciprocal library service with the Fremont Library District. 
Mrs. Littler retired in June 1966. Librarian Sophia Jochims appears to have kept things running after Littler’s departure. The Library Board hired Bill Sannwald as the new director but he didn’t come on board until January of 1967. 
In October of 1966 the Library Board purchased a new bookmobile that would be delivered in about 10 months’ time. 
Amidst it all the Library Board prepared for another referendum in November 1966.
In the September 8, 1966 issue of the Independent Register, the Library Board shared drawings and a floorplan of the proposed addition with the public. These plans were more modest than the 1964 plans and allowed the Cook house building to maintain its prominence on the streetscape.
Later, in its November 17, 1966 issue, the Independent Register published photographs of the crowded Cook Memorial Library accompanied by an editorial which declared “A Need Which Cannot Be Denied.”
In 1964, the Library Board had failed to pass a referendum to build a new library by 47 votes. Would they succeed this time?
On November 19, 1966 voters voted in favor of the referendum by 221 votes. The referendum allowed the board to take out $450,000 in bonds and allowed a 38,000 square foot addition to be built.  What made the voters say yes? Was it the favorable press? Was it the scaled back design? Was it the need for more space, or the promise of reuniting children’s and adult services in the same building? Regardless of the reason for passing the referendum, the board could finally move forward with exciting expansion plans.
While the Cook Memorial Library Board started to work on construction plans, there was another issue. The Village Library Board, which had come into being in the early 1920s, remained in operation alongside the Township Library Board. The sole purpose of the Village Library Board was to build a new library with any funds that the library received from the sale of property left by Ansel and Emily Cook. With the new addition approved, in September of 1967 the Village Library Board transferred their complete holdings of $47,615 to the Libertyville Township Library Board and disbanded soon after. 
The Cook Memorial Library had a lot going on in the autumn of 1967. The new bookmobile was delivered in August , the Village Library Board transferred their funds as described above, and new head librarian William Sannwald helped the Library Board finalize the building plans. In October the library broke ground for the long-awaited addition and construction was underway.
(Photos from library scrapbook, Cook Memorial Public Library District collection)
While the building expanded, so did the library’s services. Cook Memorial Library joined the North Suburban Library System in November 1967, which opened up more resources and networking opportunities for the librarians, and offered greater borrowing opportunities for the patrons. 
As the building construction drew to completion, Bill Sannwald accepted a new position as director of the Minneapolis Public Library and left in October of 1968.  The Township Library Board searched for a new head librarian to lead them in their new home.
Fred Byergo became the new director in September 1968.  One of his first duties was managing the move to the new building. In November, library employees, Library Board members, Boy Scouts and other volunteers formed a human chain to pass books from the former Cook house to the new library.
The building was dedicated on November 10, 1968.
The library continued to use the first floor of the Cook House for book preparation for the bookmobile and for meeting room and display space. The second floor was turned over to the Libertyville-Mundelein Historical Society. 
You can imagine how excited the community, not to mention the library staff, were about the spacious new addition.
The Children’s room returned to be part of the library, located in a bright room with windows overlooking Cook Park. This is where the Fiction Room is today.
There was plenty of room for the collection of books, magazines, and newspapers, There was plenty of room for reading and studying.
There was plenty of room.
The following sources used in this post can be found in the Cook Memorial Public Library District collection.
- Meeting minutes of the Board of Directors of Cook Memorial Library of Libertyville Township, February 10, 1965.
- Meeting minutes of the Board of Directors of Cook Memorial Library of Libertyville Township,February 9, 1966.
- Meeting minutes of the Board of Directors of Cook Memorial Library of Libertyville Township, July 20, 1965.
- Meeting minutes of the Board of Directors of Cook Memorial Library of Libertyville Township,March 5, 1966.
- Meeting minutes of the Board of Directors of Cook Memorial Library of Libertyville Township, June 14, 1966.
- Meeting minutes of the Board of Directors of Cook Memorial Library of Libertyville Township,October 11, 1966.
- Independent Register, November 11, 1966, p. 1.
- Independent Register, September 28, 1967, p. 1.
- Meeting minutes of the Board of Directors of Cook Memorial Library of Libertyville Township, August 8, 1967.
- Independent Register, November 16, 1967, p. 1.
- Waukegan News-Sun, July 5, 1968, p. 29.
- Independent Register, August 29, 1968, p.
- Meeting minutes of the Board of Directors of Cook Memorial Library of Libertyville Township, June 11, 1968.