How a 1951 Book Shaped the Way Mérida Grew

In 1951, a Yucatecan architect named Leopoldo Tommasi published a book in Mexico City called La ciudad de ayer, hoy y mañana — The City of Yesterday, Today, and Tomorrow. It was part history, part complaint, and part urban vision. Seventy-five years later, researchers say it quietly shaped the way Mérida looks today.

Tommasi was born in Mérida in 1899 and trained at the Royal Academy of San Marcos in Madrid. He worked as an architect, sculptor, playwright, and public official. He watched the city double in population during the henequen boom — from about 36,000 residents in 1895 to more than 62,000 by 1910 — and double again by 1950, reaching 142,000. That kind of growth, spread haphazardly across the flatlands around the old colonial core, bothered him deeply.

His book traced Mérida’s urban form from its Prehispanic origins through the 1950s, using a series of eight maps to show how the city had expanded. He argued that Mérida had always grown as a kind of “urban land grant” — first as a Spanish colonial grid laid out for 100 soldiers, then ringed by Indigenous neighborhoods, then by revolutionary-era worker colonies after 1915. The result, he wrote, was a sprawling, low-density city with no regulatory plan and no real structure.

What Tommasi may not have fully understood, according to researcher Marco Aurelio Díaz Güemez in a recent analysis published by UADY’s Faculty of Architecture, is that this “disorder” was in fact a deliberate policy. The wave of working-class neighborhoods built around Mérida from 1915 onward — places like the colonias Jesús Carranza and Francisco Madero — reflected a post-revolutionary government philosophy of distributing land to workers. It was a kind of urban reparto, a parallel to agrarian land reform.

Still, Tommasi’s diagnosis of the problem had a real impact. In 1952, Yucatán Gov. Tomás Marentes Miranda brought him on as head of the Department of Engineering and Public Works, and simultaneously hired Mexico City architect Mario Pani to draft a master plan for Mérida. Pani’s team, working from Tommasi’s historical maps, proposed what amounted to a local version of Le Corbusier’s Athens Charter: denser development, the separation of residential and industrial zones, and a ring road around the old city.

That specific plan was never formally presented — the administration lasted only 16 months. But Pani’s team published their findings in a 1953 architecture journal, and the ideas continued to circulate. By the time Gov. Carlos Loret de Mola Mediz hired a UNESCO-IPN planning team in the early 1970s, the proposals had evolved, but the Tommasi framework remained underneath. That team produced the master plan that created the Circuito Colonias and the Periférico — the ring roads that still define the city’s structure today.

In 1972, Infonavit began filling in the space between those rings with new housing fraccionamientos. The city held relatively steady within those limits until 2003, when Mérida’s city government opened construction beyond the Periférico, touching off the current era of outward expansion.

Díaz Güemez presented an earlier version of this research at the First Forum on Mexican Urban History at Universidad Iberoamericana in Mexico City in June 2024.

Tommasi, who died in 1976, reportedly grew uncomfortable with his own book in his later years, telling architecture students not to bother reading it. Perhaps he sensed the irony: his own ideas had helped close the city in, only for development to eventually burst past those same boundaries.

Mérida today is home to more than 1 million residents and has grown well beyond the Periférico. The metropolitan zone now officially encompasses 13 municipalities.

Quick Facts: Leopoldo Tommasi López

• Born: Mérida, 1899; died: 1976
• Trained at the Real Academia de San Marcos, Madrid
• Designed the Carlos R. Menéndez library building in Mérida
• Published La ciudad de ayer, hoy y mañana in 1951
• Served as head of the Dirección General de Bellas Artes, 1970–75
• His maps and urban analysis influenced two official master plans for Mérida

Source: Cuadernos de Arquitectura de Yucatán, No. 38 (2025), UADY Faculty of Architecture; “La morfología urbana de Mérida según Leopoldo Tommasi” by Marco Aurelio Díaz Güemez