By Olivia Fleming

PUBLISHED: 09:34 EST, 27 June 2013 | UPDATED: 08:13 EST, 28 June 2013

Anna Wintour has used her very first tweet to weigh in on the Supreme Court ruling against the Defense of Marriage Act.

Posting on Vogue's official Twitter account, the editor in chief included her initials at the end of poignant message to indicate that the tweet came from her.

'Today's rulings are a big step forward for all Americans striving to achieve equality. I couldn't be happier or more proud. —A.W.' wrote the 63-year-old.

A spokeswoman for Vogue revealed that it was Ms Wintour's idea to send the tweet, after the Defense of Marriage Act, or DOMA, was ruled unconstitutional by the Supreme Court yesterday, giving same-sex couples the same federal benefits and equal protection as heterosexual partners.

'Anna has always been vocally committed to the cause of marriage equality,' the spokesperson told Ad Age.

'She felt it was important to use her first tweet to express her support for a cause that she holds dear to her heart.'

It is unclear whether Ms Wintour, who has been an outspoken lesbian, gay, bisexual and transgender (LGBT) rights advocate for years, and was honored with an Ally for Equality Award from the Human Rights Campaign in February, will continue tweeting for Vogue.

'You will just have to follow us and see,' the spokesperson said.

Although she saved her first tweet for the monumental ruling, Ms WIntour isn't the only celebrity to share her thoughts on the historic ruling.

'Goodbye #DOMA #Prop8. Hello #equality,' Ben Affleck tweeted.

Meanwhile Demi Lovato wrote: 'Gay, straight, lesbian, bi.. No one is better than any one else. What an incredible day for California AND for equality.'

And even Leonardo DiCaprio weighed in on the subject. 'Historic day. Well done #SCOTUS,' he remarked.