There is some disagreement among sources as to who should receive the majority of credit for designing Memorial Amphitheater. Lemos, Morrison, Warren, and Hewitt specifically name Thomas Hastings, as does the United States Commission of Fine Arts and others. But other sources name Frederick D. Owen, a civilian engineer working for the Corps of Engineers (and who also designed the Flag of the President of the United States). Owen is named by architectural historians Butler and Wilson and by historian Rick Atkinson. The Arlington Memorial Amphitheater Commission is not clear as to who deserves the credit, as it notes that Owen "drew the first sketches for plans for the great Memorial in 1904" and later gave "suggestions and advice as to the form of the Memorial". Owen's significant role is made clear by the AMAC in other ways as well: He designed the memorial trowel used by President Woodrow Wilson to lay the cornerstone; he served on the reception committee for the cornerstone laying ceremony; he co-chaired the planning committee for the 1921 dedication; and he chaired the reception committee for the dedication. But the AMAC also said Carrère and Hastings prepared the plans for the building, provided the explanation of the design to the AMAC, and was named by Congress as the architects.