About 30 years before that eventful canoe trip, American writer Mark Twain summed up the spirit of Chicago when he wrote Life on the Mississippi. Chicago's citizens, he wrote, are:

… always rubbing a lamp and fetching up the genii … contriving and achieving new impossibilities … [Chicago] outgrows her prophesies faster than she can make them, she is never the Chicago you saw when you passed through the last time.

Once they got back to their office at Steinway Hall, Walter and Marion furiously rubbed the magical lamp, fetching up the genii they both knew were within them. Working up the plans for the competition would be a monumental task. The project would require many drawings, from rough sketches to detailed drawings and perspectives. Then they would all have to be packaged up securely and sent on the long journey by train and sea to Australia. While the ideas for the plan of the city would largely be Walter's, their visual production, their transition from Walter's rough concepts and sketches to the detailed, carefully inked and painted works, would be the responsibility of Marion and her team.

What happened next was the result of a unique partnership between architect and architect, town planner and delineator, man and woman, husband and wife, two lovers, working side by side to achieve a life's vision, working together with all the instinctive movements of two highly trained dancers. The new bride and groom were coming together for the biggest challenge of their lives.

Exactly what went on between Marion and Walter over that time has never been documented. Walter was the town planning expert, but it would be Marion who would oversee the drawings needed to display her husband's grand designs, just as she had done for Wright. While it was Walter who had the lifelong dream of designing great cities, Marion had some of the best architectural drawing skills in America at the time. She was determined to use all her skills and energy to see her husband realise his long-held dream. But she was also an experienced architect in her own right, experienced in perspectives of places she had never been to, and brought her own vision to the project. Walter had never left America, but Marion had already seen some of the finest cities in the world.

Marion would have deferred to Walter's superior knowledge of town planning and landscaping but, as she had done at times with Wright, she would also have been his strong-minded sounding board as he worked through his ideas.

Like Washington, DC, the selection of the site for the Australian capital, away from the main established cities, had been a compromise decision to keep the different interests involved happy. The Australian states had decided that the capital should be in a completely new site, somewhere between the two main cities of Sydney and Melbourne.

Chosen after years of argument and deliberation, the site was almost barren limestone plains, used mainly for grazing sheep, far away from any sizeable towns. The Griffins studied the wide cycloramic works, trying to imagine what the site was like, what Australia was like, a place on the other side of the world.

The instructions suggested planning for a city of 25,000 inhabitants, which could eventually expand to cater for around 100,000. It was a fraction of the two million people who lived in Chicago.

The vision of Daniel Burnham's White City, the World's Fair of 1893, was still imprinted in their minds. Walter had cycled to the site many times as a teenager as it was being built, watching how Frederick Olmsted, the designer of Central Park in New York, had created a beautiful site with lagoons and a wooded island from a swampy land. He knew that carefully crafted, stylish water features were an essential part of any city of status, and the river in the middle of the plain, the Molongolo River, provided the opportunity for just that.

The Griffins believed that cities should be carefully designed to fit into the landscape, following the contours of the topography, with as little damage to the natural surroundings as possible. The site, with its wide river floodplain surrounded by hills, was a natural amphitheatre. As they began to imagine a new capital, it was not hard to see that Marion may have been reminded of the idea of the seven hills which surrounded the ancient city of Rome.

The focal point of the city, they decided, would be Mount Kurrajong, which had a commanding view northward, across the river and up to the grand higher Mount Ainslie.

The Griffins decided that Mount Kurrajong should become the site of the Capitol but it would not be like Capitol Hill in Washington. Their concept was like the Capitol in Rome. In ancient Rome, the Capitoline Hill was one of the citadels of the city. By 1896, when Marion walked around Rome with her brother, it had become an impressive space, designed by Michelangelo, with a central piazza surrounded by museums, which stored some of the city's treasures. It was a place of the people, while the forum, where the business of government took place, was set in the city below.

Their Australian Capitol would have a grand building and public spaces on Mount Kurrajong. There would be two official residences on either side, one for the prime minister and one for the governor-general. In the centre, as in Rome's Capitol, there would be public areas with a striking public building storing national treasures and the official archives. The houses of parliament would be situated below the Capitol, on Camp Hill, with other government buildings farther down, set around a central water basin. The basin would connect to the central lake through a water gate. They decided there would be five wide avenues radiating from Capitol Hill. Two would cross the river basin to the two other main centres servicing the people – a municipal centre and a market centre.

The plan, they decided, would have two main axes – the land axis from Mount Kurrajong north to Mount Ainslie, with the government buildings on the south side and most of the people living and enjoying life on the north, and a perpendicular water axis along the line of the river.

As Walter focused on the city design, Marion worked on the drawings. Her years of experience working for Wright had taught her how a beautifully rendered drawing could bring an architectural concept to life. Marion's lush use of trees and foliage in her renderings of his architectural ideas had worked to complement the strong horizontal lines in Wright's work. Translating Walter's grand plans for a new city would be a greater challenge for the new bride who had great ambitions for her talented husband.

They worked on a portfolio of drawings. There was the one of the city plan set into the official contour map, a requirement for all competitors. Then they did a bird's-eye view of the site, called City and Environs, which looked down on the city from a far greater height. Almost as tall as a man, it was done in ink on cloth, coloured with a sepia-toned wash and lightly varnished. Looking a little like a series of interlocking snowflakes, it highlighted the powerful geometry of the plan.

The buildings were drawn to a miniature scale, which taken together looked like a magical fairy kingdom. The drawings of the military college and the cathedral next to it could have been scenes from a medieval village on a distant hill. There were two wide panoramas made up of four panels each, which were to be joined together. Just to make it clear to those assembling them, they were highlighted by a horizontal, burnished gold band, which stretched across the width of the horizon across the panels. It looked as if it could be a wide, flat mountain range in the distance. Or, with some imagination, the dark gold band could have been a wide shallow river, with the tiny buildings set into the creek bed below it, like the miniature world in the rivers around Chicago, which so fascinated Marion when she and Walter used to paddle along. It was another world that simply demanded a closer inspection.

[After Walter died in 1937] Marion wanted to make one last visit to see Canberra, the city she and her husband had created. She had one last wish. She wanted to see the view from the summit of Mount Ainslie, the view she had imagined so intensely on a cold Chicago winter almost 30 years before. She drove up the winding hill to the top of the mountain. She looked down at the city that she and her husband had designed and saw a:

… young city and all its suburbs laid out on the ground before them, beautiful scenery and the background of mountains, streets constructed, splendid tree plantings evergreen and blooming, with street lights in all, Parliament House and other government buildings, several residential centres fairly occupied, residences, shops, theatres.

But she knew it was still unfinished.

This is an edited extract from Making Magic: The Marion Mahony Griffin Story, by Glenda Korporaal. $34.95. Available from the National Library of Australia bookstore.