During the American eclipse of 1854, photography was in its infancy. Back then, William and Frederick Langenheim were among the small number of shutterbugs who captured the event on sheets of silver-plated copper, known as daguerreotypes.

On Monday, millions of folks using mobile phones and digital cameras will document what has been dubbed "the Great American Eclipse" and rapidly post snaps of the sun's corona peeking from behind the moon on Instagram and Facebook.

The anticipated deluge of social media will doubtless benefit those unable to see the spectacle first hand. But make no mistake, eclipse veterans say photos do not compare to the splendour of truly standing in the moon's shadow.

Jeff Rosenheim, a photo curator at New York's Metropolitan Museum of Art, who dusted off the Langenheim images to celebrate the occasion, offers simple words of advice: Don't let selfies spoil the magic moment.

"We live in a world of media replacing direct experience… It would be nice to have a takeaway from the experience, but I also hope that people actually have the experience," Rosenheim told Al Jazeera.

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Total solar eclipses are not rare and occur on average every 18 months. Many can only be seen from remote oceans, deserts and icy wastes; Monday's event is remarkable because it cuts right across the world's third most populous nation.

Viewers can watch the moon's shadow in 14 states, starting at 10:16am (17:16 GMT) near Lincoln Beach, Oregon, and then racing across mountains, woods and prairies to reach McClellanville, South Carolina, 93 minutes later at 2:49pm (21:49 GMT).

More than 200 million people live within a one-day drive of the path of totality, the 110km-wide tract along which the sun is wholly obscured except for the ghostly glow of its corona, driving talk of the most viewed eclipse in history.

According to Guy Brandenburg, 67, a retired teacher from Washington, DC, it is worth the trip. He is heading to Lander, Wyoming, to watch his third eclipse through a home-made telescope, and raves about the "most amazing natural phenomenon".

Veterans talk of temperatures dropping and breezes as sunset-like hues cross a sky that deepens into a twilight blue. Stars brighten, and planets come into view as animals and birds behave strangely, as they would at dusk.

"You've seen photos and videos. None of them, not a single one, does justice to how incredibly beautiful the spectacle is," Brandenburg told Al Jazeera. "You can see things you've read about, like the corona and the chromosphere, that are directly related to our very being."

All of North America will experience a partial eclipse, though Brandenburg warns anybody outside the zone of totality will not see the sun's corona. Even a 99 percent obscuration comes a distant second to the marvel of a full eclipse.

Even so, office workers in New York, Los Angeles, and elsewhere will likely stretch their legs to see a partially covered sun. Their 20-minute breaks will add up to some $694m in lost productivity, estimated the hiring firm Challenger, Gray & Christmas.

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Viewers are advised to wear special sunglasses to avoid eye damage from the sun's rays. Thousand Oaks Optical, an Arizona-based supplier, has sold enough filters this year to produce some 100 million pairs of shades. Experts also warn of defective knockoffs flooding the market.

There are few secrets about eclipses. NASA, the US space agency, has catalogued five millennia of data covering the dates and durations of every eclipse from 1999BC to 3000AD. The results are available on its website.

Eclipse-chasers have had years to prepare, studying weather charts to predict cloud-free viewing spots. The West is best, apparently, with many folks bound for inland Oregon, Idaho, Wyoming, and Nebraska to dodge any rain clouds further east.

But there is no perfect strategy. Wildfires are already burning in Oregon, and tinder-dry vegetation vulnerable to fire across the Western region threatens to bring smoky skies, sudden road closures and shuttered campsites.

Rangers are on high alert as motorists flock to the remote national forests and rangelands from the Cascades to the Northern Rockies, clogging roads and straining resources as hoteliers and airlines jack up their prices.

As many as 30,000 people are expected to flock to Stanley, Idaho, which is normally home to just 68 year-round residents. Depoe Bay, Oregon, is near the site where the total eclipse will first appear. Local gift store owner Pat O'Connell predicts a "double ground zero" of visitor chaos.

Scientists are animated too. NASA plans to fly high-altitude balloons and planes for physics experiments. US science satellites will observe the sun and Earth; the US space agency will also broadcast the eclipse live from locations along the path.

Jay Pasachoff, 74, an astronomer at Williams College, holds a record for witnessing 65 solar eclipses. He has planned his 2017 trip since the early 1990s and will set up 20 telescopes and cameras among two tonnes of gear in Salem, Oregon, to measure the solar corona.

Despite having 33 total solar eclipses under his belt, he is still wowed by the "reddish horizon glow" and the "shadow bands snaking across the landscape" as "bright beads of sunlight shine through the valleys on the edge of the moon".

Some of the wonder has given way to Pasachoff's duties running a 300-strong team. "Mainly I'm nervous now about the weather and having all my equipment properly installed and everything working for when we press the buttons," he told Al Jazeera.

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There are adventurous ways to view the event. Some spectators will board aircraft that soar above any clouds and follow the path of the eclipse, making it last longer than the roughly two-and-a-half minutes enjoyed by those at ground-level.

There are wacky options too. Visitors to Charleston, South Carolina, can head to the Pounce Cat Cafe to delight in the "rambunctious" frolicking of 20 kittens during the galactic alignment, co-owner Annaliese Hughes told Al Jazeera.

Carhenge - a replica of Stonehenge made with old autos in Alliance, Nebraska – is also touted as a fun place to stargaze.

Those aboard Royal Caribbean's Total Eclipse Cruise can watch the extravaganza after listening to Bonnie Tyler belt out her 1983 hit "Total Eclipse of the Heart", with the vessel positioned in the path of totality off Florida's coast.

Others are making the day special in their own way. Mike Wilson, 27, is taking his girlfriend down to South Carolina, where he plans to propose marriage just as the eclipsing moon pulls back out of the sun's way.

"Hopefully this very beautiful ring will go from being partially lit up by the heavens to starting to be bathed in sunlight a few seconds later," said Wilson, whose name has been changed so as not to ruin the surprise.

The spectacle will be the first in 99 years to span the entire continental United States and the first total solar eclipse visible anywhere in the lower 48 states since 1979. It follows a difficult few weeks in a politically charged US.

Tensions were stoked by the Charlottesville clashes, when a young woman was killed as far-right activists marched under Nazis swastika signs, and President Donald Trump did not distinguish between the white supremacists and those rallying against them.

For Wilson and others, seeing the eclipse is a "secular pilgrimage" that offers Americans a chance to share an experience and look beyond the ideological differences that have riven this nation of 323 million people.

"I really hope that for two minutes you can just be wowed by something much bigger and fully positive. There's not a downside to this. It's not a risk, it's not partisan, it's just awe-inspiring," Wilson told Al Jazeera.

Follow James Reinl on Twitter: @jamesreinl