Photos show how Manhattan's Financial District has changed since 2001

The terrorist attacks on September 11, 2001, changed America forever. They also permanently altered New York City landscape.

Over the past 18 years, the site of the World Trade Center has become a memorial to the 2,977 lives lost on 9/11, and new buildings like One World Trade Center have been constructed.

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The terrorist attacks on September 11, 2001, took the lives of nearly 3,000 Americans and transformed the US in countless ways.

It sparked the global war on terror (which the US is now fighting in 76 countries) and the invasions of Iraq and Afghanistan, the longest war in US history and one that the Trump administration is struggling to withdraw from.

It led to the creation of the Department of Homeland Security, US Immigration and Customs Enforcement, and the Patriot Act.

And it also fundamentally changed New York City.

In honor of the 18th anniversary of the horrific attacks, we compiled 18 photos showing how Manhattan's Financial District and skyline have changed since 9/11 as the city rebuilt ground zero.