Mackall, Crounse & Moore, PLC has joined Dewitt Ross & Stevens S.C.

The newly formed DeWitt Mackall Crounse & Moore S.C. will provide clients with enhanced legal services
and efficiencies as well as access to more than 100 attorneys practicing in nearly 30 areas of
law in Wisconsin and Minnesota.

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William J. O’Brien

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Christine L. Hansen

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Bill is a distinguished business lawyer who has mastered tax-wise planning of personal estates and business ventures. His tax and estate planning experience allows him to structure transactions that help clients meet their business objectives and it involves all phases of legal consultation for businesses, including formation, contractual drafting and negotiations, shareholder agreements as well as buying, selling and merging businesses. He brings to the table a common sense approach and strategy with the goal of “get the deal done.”

His in-depth knowledge of estate tax and succession planning has given him a solid skill set which has helped to enable countless clients in transitioning their asset holdings through complicated estate planning devices and concise business succession plans. During the process, frequently he is able to offer additional suggestions clients may not have been aware of, in order to maximize the benefits of a thorough estate plan. Bill’s involvement in individual tax planning and business tax planning adds an additional level of skill to assist business owners and their families in avoiding or deferring income taxes, corporate taxes and estate taxes.


He represents closely-held businesses and their owners, including family owned businesses and individuals who are ready to retire and transition out of the business. In addition, he represents individuals in their private estate planning needs.

Notable Representations

  • Successfully represented and acted as company counsel for 27 shareholders in a stock sale of a closely held metropolitan ski facility.

  • Continually provide clients with legal guidance in the area of purchases and sales of a variety of businesses to include family-owned business, manufacturers, machine shops and more.

  • Efficiently represented a family-owned business in acquiring land for the expansion of their business facilities.

  • Acted as lead counsel while overseeing the legal issues associated with the location expansion and acquired operations for a warehousing and logistics business.

  • Throughout the years, conducted numerous tax-deferred real estate exchanges for clients in a variety of industries.

  • Negotiate, document and close numerous mergers and acquisitions for professional services firms, such as accounting and law firms.

  • Retained as transactional counsel to work with mediators and accountants to resolve and document litigation disputes among family members and their complex business interests.

  • Business & Corporate Law

    • Represented hundreds of individuals in the formation of closely-held businesses, including corporations, limited liability companies, limited partnerships and general partnerships.

    • Frequently represents entities and/or independent owners in various stages of formation, growth, contractual work, executive compensation agreements, non-competition and non-solicitation agreements as well as buy/sell agreements.

  • Estates & Trusts/Business Succession Planning

    • Represented numerous closely-held business owners in connection with avoiding, minimizing or delaying payment of estate, income and gift taxes.

    • Represented countless families in transitioning family-held businesses and real estate holdings from the first generation to the second or third generations.

  • Mergers & Acquisitions

    • Acted as buyer’s or seller’s counsel in numerous stock and asset purchase and sale transactions.

  • Real Estate Law

    • Assisted clients in significant developments of commercial warehouses and office buildings.

    • Reviewed, negotiated and drafted numerous lease agreements representing both tenant and landlord interests.

  • Tax Law

    • Assisted numerous entities and individual clients in structuring business transactions to avoid, minimize or delay income tax consequences associated with various types of business transactions.

  • Trademark & Intellectual Property Rights

    • Represented several clients in protecting and determining availability of trademark and service mark rights.

    • Assisted clients with the registration and enforcement of trademark and service mark rights.

    • Drafted and negotiated distribution, licensing and royalty agreements for intellectual property rights.

Publications & Presentations

  • Co-Author and Co-Chair “Buying, Selling and Merging Closely Held Businesses” Minnesota Institute of Legal Education, 1988, 1989, 1991, 1993, 1995, 1997, 1999, 2001

Our Locations

We are currently limiting the amount of outside visitors to the firm.  

Please work directly with your attorney who will coordinate any onsite visits to ensure the safety of our clients and colleagues.


2 East Mifflin Street, Suite 600
Madison, WI 53703
(608) 255-8891
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Greater Milwaukee

13845 Bishop’s Drive, Suite 300
Brookfield, WI 53005
(262) 754-2840
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2100 AT&T Tower,
901 Marquette Avenue
Minneapolis, MN 55402
(612) 305-1400
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Get to know us

DeWitt LLP is one of the ten largest law firms based in Wisconsin, with an additional presence in Minnesota. It has nearly 140 attorneys practicing in Madison, Metropolitan Milwaukee and Minneapolis in over 30 legal practice areas, and has the experience to service clients of all scopes and sizes.

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We are an active and proud member of Lexwork International, an association of mid-sized independent law firms in major cities located throughout the Americas, Europe and Asia and an active member of SCG Legal, an association of more than 140 independent law firms serving businesses in all 50 state capitals and major commercial centers around the world.


Best Lawyers 2013 – 2020
Super Lawyers 2020
Compass Award 2012
Top 100 Lawyers: National Trial Lawyers Association


While we would like to hear from you, we cannot represent you until we know that doing so will not create a conflict of interest. Accordingly, please do not send us any information about any matter that may involve you until you receive a written statement from us that we represent you (an “engagement letter”). You will not be a client of the firm until you receive such an engagement letter.

The best way for you to initiate a possible representation is to call DeWitt LLP at 608-255-8891. We will make every effort to put you in touch with a lawyer suited to handle your matter. When you receive an engagement letter from one of our lawyers, you will be our client and we may exchange information freely.

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