Welcome to PetersonMangum, LLC


non-profit management consulting


Cicely Peterson-Mangum,Esq.
  Managing Partner & Principal Consultant 


Our Work

 Established in 2017, PetersonMangum, LLC helps organizations increase their effectiveness and navigate critical junctures through strategic consulting and leadership support. Our practice seeks to identify and cultivate internal and external relationships so that organizations can leverage the power of deep collaboration. PetersonMangum draws upon a combined 21 years of experience to unlock increased impact through strategic planning, organizational capacity building, stakeholder cultivation, board development, and fundraising.


  • Clementine Montessori School | strategic planning retreat facilitation, comprehensive board development (retreat, audit, and training), and full three-year strategic plan design

  • Mantua Civic Association | multi-session strategic board retreat facilitation and major funder grant report preparation

  • PHILADANCO! | board and organizational model consultation, fundraising recommendations, and strategic advising

  • Lil' Filmmakers | business and program model evaluation, strategic planning consultancy, and leadership coaching

  • Compass Rose Spatial Design | business and program model evaluation and leadership coaching

  • Education Plus Health | grant proposal writing and document review/editing

  • Enon Coulter Community Development Corporation | organizational and project implementation consulting, communications strategy, and external relations consulting


Cicely Peterson-Mangum, Esq., Managing Partner &
Principal Consultant


Cicely is a strategic leader who has worked in both non-profit and for-profit sectors including education, economic development, government, and law. Cicely most recently served as Executive Director of Drexel University’s Dornsife Center for Neighborhood Partnerships, where she functioned as a primary liaison between Drexel’s academic programs, community partners, and philanthropists, and advanced community-inspired and data-driven initiatives. Cicely led the Dornsife Center’s strategic planning process, developing a collective vision and strategic programming priorities for the organization.

Prior to joining Drexel University, Cicely served as Interim Chief Executive Officer of Imhotep Institute Charter High School, where she successfully led the school’s charter renewal efforts. Similarly, in her role as Executive Director of Logan Community Development Corporation, she revived a defunct clearinghouse for relocation payments to victims of Logan sinking homes into an organization with a refreshed vision and mission to implement transformative community development. Cicely also directed commercial corridor revitalization efforts at Mt. Airy USA (now Mt. Airy CDC), where she was appointed the first Executive Director of the Mt. Airy Business Improvement District.

As a practicing attorney, Cicely was a tax litigator at Linebarger Goggan Blair & Sampson, LLP, representing clients in the municipal and financial services sectors. She is a sought-after speaker and expert in neighborhood development, education innovation, economic development, and leadership. The recipient of several awards for community leadership, she was listed among the Philadelphia Tribune’s "10 People Under 40 to Watch" and the Philadelphia Business Journal’s “40 Under 40.”

Cicely holds a J.D. from Western New England University School of Law and a B.A. from the University of Virginia. She earned a certificate in Nonprofit Management from La Salle University and is a graduate of the Nonprofit Executive Leadership Institute (NELI) of Bryn Mawr College Graduate School of Social Work and Social Research. Cicely is a member of the inaugural class of the Philadelphia African-American Leadership Development Forum. She serves on the board of trustees of the Seybert Foundation and the University of Virginia's IDEA Fund (inclusion, diversity, equity, and access), and previously was on the board of the Philadelphia Association of Community Development Corporations.


Derren A. Mangum, Partner & Consultant

Derren brings together decades of professional writing with over nine years of non-profit fundraising experience to assist organizations with the synthesis of compelling communication across many aspects of their operations. He specializes in a thoughtful process of investigation and iteration to help craft persuasive materials through robust, concise content.  Derren is currently Director of Institutional Giving for Opera Philadelphia, where he provides leadership for the organization's foundation, corporate, and government campaigns, which account for approximately $4 million annually. Prior to his work at Opera Philadelphia, Derren worked in online and corporate communications, real estate settlement, and web design, always maintaining a core focus on written communications both professionally and personally.

Derren holds a B.A. in Rhetoric and Communications Studies from the University of Virginia and earned a Certificate in Editing from Temple University Center City. He is a member of the  Education Nominating Panel, which was tasked to provide candidates to the mayor for the Philadelphia's new Board of Education. Derren has just completed over five years of board service for the C.W. Henry School PTA, most recently as president. 



We were so fortunate to have Cicely and Rhonda [Anderson of Anderson Law Group] facilitate our board retreat and strategic planning session! After working with them, we had a thoughtful and thorough strategic plan to guide our work for the next three years. And our board was more connected, more conscious of our responsibilities as trustees, and more energized to do the work we committed to in our plan. We were so pleased with Cicely and Rhonda that we quickly hired them again to do a board orientation at the start of the next year and were equally satisfied with both the in-session learning and tangible skills and tools they provided during and after the session.
— Reynelle Staley, Chair of the Board of Trustees, Clementine Montessori School
I’m grateful to Cicely for her consulting work with my organization, and I really learned a lot from our coaching relationship. Her patient and positive approach to communication established great trust and comfort, and I felt she was a partner invested in my success, offering logical suggestions at the right time. Our work inspired me to step out of my introverted shell and feel confident about the accomplishments of Lil Filmmakers.
— Janine Spruill, Executive Director, Lil Filmmakers
The MCA Leadership Retreat was engaging, insightful and renewing. We learned so much about ourselves while focusing on the issues that are a priority for our organization. Moreover, we greatly appreciate the ‘before, during and after’ support and guidance. It meant a lot.
— Gwendolyn Morris, Secretary of the Board of Directors, Mantua Civic Association


PetersonMangum, LLC
7715 Crittenden St, #165
Philadelphia, PA 19118


Name *